Precision Dowel Pins for Manufacturers: A Comprehensive Guide
Posted: August 24, 2023 Filed under: dowel pin, Fasteners, Inch, Metric, Metric Dowel Pins, Mil-Spec, Pins, PRECISION DOWEL PIN | Tags: ASME B18.8.2, Bulk Pins, Custom Dowel Pin, Dowel Pins for Manufacturers, Fasteners, Functional Equivalent Pins, Hardware, Heavy Duty Fasteners, Inch Dowel Pins, Mechanical Fasteners, Metal, Metric Dowel Pins, Mil-Spec Dowel Pins, MS16555, Pins, Pins for manufacturers, Precision Dowel Pin, Precision Fasteners Leave a comment
Considering Precision Dowel Pins for Your Next Project?
When you’re in the heart of the manufacturing industry, precision is not just a luxury; it’s a necessity. Components like dowel pins may seem small and inconsequential, but in this realm of precision manufacturing, they are paramount to ensuring accurate alignment and fit. Precision dowel pins, in particular, play an indispensable role in guaranteeing accurate alignment and secure fastening in a broad spectrum of applications. But with various tolerances, standards, materials, and sizes available, how do you make the right choice? It is important to know and understand these factors in order to make informed decisions that will meet your expectations & manufacturing needs.
What are Precision Dowel Pins?
At their core, precision dowel pins are simple cylindrical rods. The term “precision” implies that these pins are manufactured to very tight tolerances in order to ensure accurate fit in assemblies. Tolerances refer to the acceptable variation in dimensions from the specified value. The tighter the tolerance, the less variation there is—meaning that their dimensions are incredibly accurate. This precision ensures that dowel pins fit snugly into corresponding holes in two components, ensuring their exact/accurate alignment.
Standards & Tolerances
Several standards are followed in the production of precision dowel pins. The prevalent standard specifications come from the International Organization for Standardization (ISO), the Deutsche Industrie Norm (DIN), the American National Standards Institute (ANSI), and the Military Standard (MS/MIL-SPEC) of the United States. At a minimum, these standards specify the pin shape, and the diameter and length tolerance. These standards might also specify the pin hardness and surface finish. OEM branded dowel pins are handled separately and are addressed later in this blog.
ISO Standard: ISO 2338A & ISO 2338B (for unhardened pins) and ISO 8734 (for hardened pins) are common standards for dowel pins. Under these standards, precision dowel pins can be manufactured to either “M6” or “M5” tolerance classes, with “M6” being the more common of the two.
- For example, an “M6” tolerance for a 5 mm dowel pin might have a diameter tolerance of -0.014 to 0 mm. So, the pin could be anywhere from 4.986 mm to 5 mm in diameter.
DIN Standard: DIN 7 (for unhardened, solid dowel pins) and DIN 6325 & DIN 6325H (hardened, solid dowel pins). Similar to ISO standards, the typical tolerance for precision dowel pins under DIN standards is designated as “M6.” This is the standard fit for dowel pins and ensures a tight fit that might require light pressing or can sometimes be hand-driven depending on the exact material and hole conditions.
- For example, for a 5 mm dowel pin under the DIN 7 or DIN 6325 standard, the typical diameter tolerance might have and upper limit of 5.000 mm & a lower limit of 4.986 mm.
ANSI Standard: ANSI standard for dowel pins is ASME/ANSI B18.8.2. This standard defines sizes and tolerances for standard dowel pins, with the “Standard Series” being the most common.
- For example, for a 1/4 (.25) inch interference fit diameter pin, the diameter tolerance might be +0.0002 to 0.000 inch. So, the pin diameter could be anywhere from 0.2500 inches to 0.2502 inches in diameter.
MIL-SPEC Standard: MIL-SPEC standard for dowel pins, particularly those conforming to MS16555 and MIL-P-21143 have very specific tolerances to ensure reliability and consistency in critical military and aerospace applications.
- The MS16555 specifies a straight headless pin with a radius on one end and a chamfer on the other. The material can be Carbon or Alloy Steel or CRES 410 or 416 Stainless Steel. Available diameters range from 1/16 (.0626-.0628) through 1 inch (1.0003-1.0001). Lengths range from 3/16 to 6 inches long. Standard diameter tolerances are +.0002 over the nominal size.
- The M21143 specifies a a straight headless pin made of CRES 303 Stainless Steel. The Mil-P-21143/1 series has a tolerance up to +.0002 over the nominal size. The M21143/2 series has tolerance of .0002 Under its nominal size.
Material Choices
Different applications may require Precision dowel pins made from different materials. The most common materials in the market include:
- Stainless Steel: Offers corrosion resistance and is suitable for applications exposed to moisture or corrosive substances.
- Alloy Steel: Known for its strength and durability, it’s ideal for heavy-duty applications.
- Brass: Often used when there’s a need to avoid sparking or in applications with lower strength requirements (less common).
- Aluminum: Lightweight and resistant to corrosion, aluminum precision dowel pins are suitable for applications where weight is a concern (less common).
Sizes Available
The diameter of precision dowel pins usually varies from 1/32″ to more than 1″, and their lengths span from 3/16″ to multiple inches. Hence, precision dowel pins come in a wide range of sizes, but certain sizes are more commonly used across various manufacturing applications due to their adaptability and compatibility with standard components. Selecting the appropriate size for your specific application is essential for achieving a snug fit, best performance, cost-effectiveness, and durability.
OEM Branded Precision Dowel Pins
Precision Dowel Pins – OEM branded “Precision” dowel pins are manufactured by precision component brands such as Pic Design, WM Berg, Unicorp and others who have their own technical specifications and are not governed by DIN, ISO or ANSI / ASME standards. They are usually only offered in stainless steel through distributors of precision components.
What to Consider Before Buying
- Tolerance: Precision dowel pins have tight tolerances. Ensure that the pins you buy meet the specific tolerances required for your application.
- Environment: Consider the environment in which the pins will be used. If they’ll be exposed to corrosive substances or high temperatures, material choice becomes crucial.
- Custom Needs: If your application requires non-standard sizes or materials, you might need custom-made precision dowel pins.
- Quantity: Depending on the scale of your manufacturing, you may need precision dowel pins in bulk. Purchasing in larger quantities often results in cost savings!
- Supplier Reputation: Always source your precision dowel pins from reputable suppliers known for their quality and consistency.
Precision Dowel Pins at MF Supply
MF Supply is a WBE/WOSB woman owned business, and a trusted supplier of Functional Equivalents, including precision dowel pins, to OEMs, manufacturers, industry, and government. We are precision dowel pin experts, offering the full catalog of dowel pins in Inch, Metric, Military and OEM branded options in a wide selection of materials, sizes and specifications. As stocking distributors, many precision dowel pins are available and ready to ship today from our national distribution centers.
Browse through the links provided below to find the precision dowel pins that you need:
- Mil-Spec Precision Dowel Pins: The full range of commercial and MIL-SPEC parts (M21143, MS16555, MS9390), including parts that are USA made, DFARS and ROHS compliant.
- Inch Precision Dowel Pins: inch sizes to ASME ANSI B18.8.2 standards in alloy steel, stainless steel 18-8, 316, 400 series and hardened. Domestic and Imported options are available.
- Metric Precision Dowel Pins: Metric sizes including DIN 7, DIN 6325, and ISO 2338 and 8734 in alloy steel, A2 & A4 stainless steel
- Precision Series and OEM branded equivalents to PIC, BERG, both Inch & Metric precision dowel pins including Press-Fit A, B and Slip-Fit C series and all MD series pins in 416 and 303 stainless steel.
- Please send us a Request for Quote for any other dowel pins not listed.
- Custom made parts per print.
Your next step?
If you have additional questions or need help in selecting the right precision dowel pins for your next project, don’t hesitate to reach out to us or send us a quote request. Our team of sourcing experts is always ready to assist you on your journey to manufacturing excellence. “Finding the right screw for you” is our tag line after all!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
Over 1.5K Dowel Pins, Cotter Pins, Spring Pins, and more Now in Stock!
Posted: July 7, 2023 Filed under: Coiled Spring Pin, Cotter Pin, dowel pin, Fasteners, Hair Pin Clip, Hitch Pin Clip, Inch, Metric, Metric Dowel Pins, Pins, PRECISION DOWEL PIN, Slotted Spring Pin | Tags: Coiled Spring Pins, Cotter Pins, Dowel Pin, Fasteners, Functional Equivalent Pins, Hair Pin Clips, Hardware, Hitch Pin Clips, Mechanical Fasteners, Metal, Pins for manufacturers, Precision Dowel Pin, Slotted Spring Pins, Spring Pins Leave a comment
Are you looking for Precision Dowel Pins, Cotter Pins, Spring Pins or Hair/Hitch Pin Clips?
If you are in need of any specific type of pins or clips for your next big project, you have arrived at the right place!
MF Supply is a WBE/WOSB woman owned business, and a trusted supplier of Functional Equivalent Pins & Clips to OEMs, Manufacturers, Industry, and Government. We offer a wide selection of over 1,500 inch, metric & Mil-Spec Pins, in Alloy Steel, Steel, and Stainless Steel materials, that are perfect for a myriad of applications. You’ll find in stock Pins in many sizes including major brands and equivalents to Blue Devil, Pic Design, WM Berg, Misumi and Unicorp; so you can choose the ones that best suit your needs.
Who uses Pins & Clips?
Pins & clips are commonly used on many industries, such as automotive, aerospace, electronic, machinery, tooling, agriculture, construction and many more where reliable and convenient fastening is a must. Continue reading to learn more about the characteristics of each pin or clip currently on our website, and how they could be of use on your next project.
Coiled Spring Pins: Coiled Spring Pins, also known as Spiral Pins or Coiled Pins, are headless, hollow pins with chamfered ends, made by shaping or wrapping a steel sheet into a slightly larger diameter than the standard size. Unlike the slotted pins variety, these pins are distinguished by their multiple walls.
Uses: These pins are frequently used to join and fasten two or more components together. When the pins are inserted into pre-drilled holes, their spiral shape allows them to expand and exert radial pressure against the sides of the hole. This creates a secure and snug fit/connection. Apart from their fastening functionalities, Coiled Spring Pins can also serve as effective retaining features. They have the ability to secure various items, such as gears, pulleys, or bearings, onto shafts, effectively preventing axial movement or slippage. Moreover, these pins can be utilized to accurately position and retain other components, ensuring precise alignment and preventing undesired movement.
Cotter Pins: Cotter Pins, also known as Split Pins, are double bodied pins formed from half-round wire, a loop at one end of which provides a head. The finished part has one end of the wire extending beyond the other end, with a chiseled point.
Uses: These pins are used to anchor various assemblies by inserting them into a drilled hole in the shaft or pin and spreading the points to hold the assembly in position. When used with castle or slotted nuts, it becomes a safety locking device. An important benefit offered by Cotter Pins is their ease of removal, which enables swift disassembly or maintenance tasks. When the need arises to dismantle/disassemble components, cotter pins can be readily taken out by straightening or bending back the split end to its original position. This feature simplifies repair or maintenance operations.
Precision Dowel Pins: These pins are solid headless straight pins with a closely controlled diameter. Applications include a wide variety of uses, such as plug gage, hinge, or shaft. They are typically cylindrical in shape and made from materials such as hardened steel, stainless steel, or aluminum.
Uses: Precision Dowel Pins are widely utilized to achieve precise alignment and positioning of components. These pins undergo meticulous machining processes and are manufactured with strict tolerances to guarantee a snug and accurate fit. Precise tolerances of Dowel Pins make them excellent for achieving proper alignment of parts in high-speed assemblies, or as roller bearings in bus/truck wheel housings. By inserting them into corresponding holes in two or more parts, the dowel pins guarantee proper alignment and positioning of the parts in relation to one another. These dowel pins serve as reference points or datums, ensuring accuracy and precision throughout the assembly process.
Slotted Spring Pins: Sometimes referred to as Roll Pins, Expansion Pins, C-Pins or Tension Pins, Slotted Spring Pins are hollow, headless pins, slit longitudinally, having controlled lengths with chamfered ends, formed to a diameter somewhat greater than that of the hole into which they are to be assembled. These pins are cylindrical in shape and are able to compress and expand upon insertion into a hole. Additionally, they are commonly crafted from materials such as carbon steel or stainless steel.
Uses: Slotted spring pins are used for the purpose of securing and fastening components together. The slots present in the pin allow for compression during insertion and radial expansion, which generates outward pressure against the walls of the pre-drilled hole. This inherent self-retaining characteristic guarantees the pin’s retention and delivers a secure method of fastening. Spring pins are economical because they can simplify product design by replacing more expensive fasteners such as taper pins, set screws and straight pins. Stainless steel Spring Pins are commonly used in electronics and food industries.
Hair/Hitch Pin Clips: Hitch Pin Clips, also known as Hair Pin Clips, Bridge Pins or R-Clips, are double-bodied pins formed from round wires. These pins are formed in a way where one end is bent approximately 180° so that the two resulting sides meet or come close to meeting. The final pins have one side that remains straight, while the opposite side has one or more turns permanently formed into it.
Uses: Hair/Hitch Pin Clips are designed to serve as a mating part to several other pins. They provide a hassle-free way to attach and detach components without the need for additional tools or complicated fastening mechanisms. Hitch Pin Clips also act as a safety feature, ensuring that the connected components remain intact during operation. When the need arises to remove or replace a pin, Hitch Pin Clips present a simple and time-saving solution. By simply compressing the curved end and sliding it out of the hole, the clip can be easily removed. Hence, this allows for quick disassembly, maintenance, or component replacement without the requirement of specialized tools or lengthy procedures.
In-Stock Pins & Clips at MF Supply
We currently have in stock over 1,500 Pins & Clips in inch, metric & Mil-Spec sizes. The most common material options available are: alloy steel with bright or ebony black oxide finishes; steel with thermal black, mechanical zinc, zinc, and zinc phosphate finishes; and passivated stainless steel—including series A2, T321, 18-8, 300, 303, 316, 400 416, & 420.
Browse through the links provided below to find the Pins or Clips that you need, and that are currently available on our website.
- Inch Coiled Spring Pins: Stock sizes include 1/16 to 3/8 in Steel with a Thermal Black finish, and in 420 Stainless Steel.
- Inch Cotter Pins: Stock sizes include 1/16 to 1/2 in Steel with a Chisel Point and Zinc Plating, as per standard ASME B18.8.1 specifications.
- Mil-Spec MS9245 Cotter Pins: Stock sizes include 1/32 through 5/32 in T321 Stainless Steel.
- Inch Precision Dowel Pins: Interference / Press Fit & Slip Fit Dowel Pins in 300 Series Stainless Steel; Dowel Pins in 316 Series Stainless Steel; and Dowel Pins in Alloy Steel with Bright or Ebony Black Oxide finishes.
- Metric Precision Dowel Pins: Stock sizes include M1 through M10 diameters in 18-8, 300, 303, A2 Series Stainless Steel; and M2 through M10 diameters in 416 Stainless Steel.
- Mil-Spec Precision Dowel Pins: MS16555-1 through MS16555-145, MS16555-301 through MS16555-444 & MS16555-601 through MS16555-744, including between-spec sizes; and Mil-P-21143 Series in 303 Stainless Steel.
- Inch Slotted Spring Pins: Stock sizes include 1/16 to 1/2 in Steel wth a Thermal Black or Mechanical Zinc Finish, 420 Stainless Steel, and Stainless Steel materials—as per standard ASME B18.8.2 specifications.
- Metric Slotted Spring Pins: Stock sizes include M2 to M8 in Steel with a Thermal Black Finish, as per standard ISO 8752 specifications.
- Mil-Spec MS16562 Slotted Spring Pins: Stock sizes include 1/16 through 1/2 in Steel Zinc Phosphate.
- Inch Hair Pins / Hitch Pin Clips: Stock sizes include .028 to .243 in Steel Zinc.
Our Pins & Clips are competitively priced. Don’t wait! Visit our website today to place an order, or Request a Quote and we will follow up with you.
Can’t find what you’re looking for?
Can’t find what you are looking for on the list? Reach out to us today, and our MF Supply team of sourcing experts will help find what you need. “Finding the right screw for you” is our tag line after all!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
Buyer’s Guide to Metric Dowel Pins Refreshed for 2023!
Posted: February 28, 2023 Filed under: DIN 6325, DIN 7, dowel pin, ISO 2338, ISO 8734, Metric Dowel Pins, Mil-Spec, PRECISION DOWEL PIN Leave a comment
7 Things to Know When Buying Metric Dowel Pins
This guide is a follow up to our Dowel Pin Buyer’s Guide published last week, on February 23, 2023. This post is specifically written to share with you the available options when it comes to procuring precision Metric dowel pins.
Our goal is to help simplify the buying process and guide you in the critical selection factors for this sometimes complex and confusing category of fasteners.
1. What standards are Metric Dowel Pins made to?
Metric dowel pins are tricky because they fall into two buckets:
- DIN / ISO standard – These metric Dowel pins are readily available in the commercial marketplace and in addition to your suppliers, can be procured through national catalogers like Mcmaster-Carr, Grainger and Holo-Krome. They come on steel and stainless steel.
- Precision Metric Dowel Pins – These “Precision” dowel pins are manufactured by precision component brands such as Pic Design, WM Berg and Unicorp who have their own technical specifications and are not governed by DIN or ISO standards. They are usually only offered in stainless steel through distributors of precision components.
2 . What are the specific criteria I can select for Metric dowel pins?
Here is a list of the criteria and available options available:
- Size
- Material
- Hardened or Unhardened
- End style
- Tolerances
3 . Can you list the standard and precision dowel pins available off the shelf?
- DIN 7
- DIN 6325 & DIN 6325H
- ISO 2338A & ISO 2338B
- ISO 8734
- PRECISION UNHARDENED PRESS FIT DOWEL PINS SS303
- PRECISION HARDENED DOWEL PINS SS416
4. Which types of metric dowel pins are available in which sizes and materials?
Use this handy grid to understand the sizes and materials available in each Metric dowel pin style.
Standard |
Ends |
Materials |
Tolerances / Fit |
Hardness |
Diameters |
DIN7ISO 2338ISO 2338A |
Rounded or beveled |
Steel (least common)300 Series Stainless Steel includingA1=18-8, 303, 304A4=316 |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M.8-M20 |
ISO 2338B |
Rounded or beveled |
300 Series Stainless SteelA1=18-8, 303, 304 |
H8 diameter tolerance |
Unhardened |
M1.5-10 |
DIN 6325DIN 6325HISO 8734AISO 8734 |
Rounded on one endBeveled on one end |
Alloy Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 52-62 |
M1-M25 |
Precision Unhardened |
Rounded |
300 Series Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M1-M12 |
Precision Hardened |
Rounded on one endBeveled on one end |
416 Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 36-42 |
M2-M10 |
Important note: All pin options may not be available in all sizes and materials.
5. When ordering, do I need to specify the dowel pin tolerance or call out attributes such as standard, undersized or oversized fit?
Metric dowel pins can show up under DINs and ISO numbers, including : DIN 7, DIN 6325, and ISO 2338 and 8734. When ordering DIN/ISO dowel pins it is best to include the Diameter, Length, Material, DIN or ISO and tolerance. For non DIN/ISO Precision metric dowel pins, you can order by the manufacturer part number, such as Pic (MDP series), WM Berg (DM Series), or Holo-Krome.
6. Can I specify if I need radius (round) or chamfer (bevel) on the pin ends?
The pin style will depend upon the spec and the material. Precision dowel pins may come with either a double chamfer, double radius, or a radius on one end and a chamfer on the other end. Check with the handy grid above for guidance.
Important note: The configuration of the ends of unhardened metric dowel pins are at the discretion of the manufacturer. If you have a specific style requirements, you might need to special order which usually involves a minimum and a lead time.
7. What if I need domestic or DFAR certified Metric dowel pins?
If you are ordering by a Precision Manufacturer part number, you are in luck! Most of the stainless steel pins produced by Pic, WM Berg and Unicorp qualify as DFAR compliant and full certifications with material certs and test reports are often available for USA made parts for a fee.
Metric Dowel Pins at MF Supply
We offer:
- The full range of commercial Metric Dowel pins including parts that are USA made, DFARS and ROHS compliant.
- Metric sizes including ASME ANSI B18.8.2, DIN 7, DIN 6325, and ISO 2338 and 8734
- Metric Precision Dowel pins including Press-Fit Series and all MD series pins in 416 and 303 Stainless Steel.
- Brand names and generic equivalents.
- Custom-made parts per print in non-standard sizes and exotic materials and finishes.
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
The Buyer’s Guide to Dowel Pins You Must Have Today! Updated for 2023!
Posted: February 23, 2023 Filed under: dowel pin, Mil-Spec, MS16555, MS16556 and Mil-P-21143., PRECISION DOWEL PIN Leave a comment
MF Supply is a trusted Supplier of Precision Dowel Pins for manufacturers. Through our extensive assortment of Inch, Metric, Commercial, Mil-Spec and OEM brand names and equivalents, we offer our customers quality imported and domestic dowel options. Our products are competitively priced with fast delivery from multiple distributions centers across the USA. Our goal is to help simplify the buying process for this sometimes complex and confusing category of fasteners.
8 Things to Know When Buying Dowel Pins
If you are a manufacturer working with complex assemblies or fixtures, then you’re likely very familiar with precision dowel pins. Commonly used as a hinge, shaft or pivot to locate or hold assembled parts together, dowel pins can withstand frequent insertion and removal without distortion. They are broadly used across various applications in many industries, including: aerospace, electrical motors, hydraulic equipment, instrumentation, tooling and fixtures, machinery, military and many more.
Our goal is to help simplify the buying process for this sometimes complex and confusing category of fasteners.
1. What is a precision dowel pin?
Dowel pins are solid, headless cylindrical shaped straight metal pins with a centerless ground finish. Manufactured to precise fractional diameters and lengths, dowel pins come in a variety of sizes, styles, designs and materials. This variability can cause confusion among buyers, engineers and end-users alike.
2. What materials and platings are available?
Precision dowel pins are available off the shelf in alloy steel (typically hardened) and stainless steel grades 18-8/303, 316 and 416 (typically hardened). Other exotic materials or special finishes are available for special order with a lead time.
3. What sizes are available?
Standard sizes include inch from 1/16″ to 1″ diameter, and metric from M1 to M20 diameter. Length options vary by diameter. Other diameters and special lengths are available for special order and usually involve a lead time.
4. When ordering, do I need to specify the dowel pin tolerance or call out attributes such as standard, undersized or oversized fit?
Precision dowel pins often show up under their MIL-SPEC numbers, MS16555, MS16556 and Mil-P-21143. Metric dowel pins might show up under the following DINs and ISO numbers: DIN 7, DIN 6325, and ISO 2338 and 8734. Dowel pins might also show up under a manufacturer part number such as Pic, WM Berg, Unbrako or Holo-Krome.
If you are ordering by MIL-SPEC, manufacturer’s part number or DIN, then the general attributes including tolerance and style are known. Here are a few of the other options that will help you order the correct pin:
- The most common standard inch or imperial sized precision dowel pin is made to the ASME ANSI B18.8.2 spec and has a diameter tolerance of -0.00 / +0.0002 and length tolerance of +/-0.010. For example, a ¼” (0.25) diameter standard dowel pin will have a diameter between 0.2500–0.2502″.
- The standard metric tolerance is related to the DIN. Both DIN 7 and DIN 6325 have a standard m6 diameter tolerance of +0.012mm / +0.004mm and a length tolerance related to the specific pin length.
- Undersized series dowel pins are used for inconsistent holes. They have a basic diameter 0.0002″ under the nominal diameter. For example, a ¼” (0.25) diameter undersized dowel pin will have a diameter between 0.2500–0.2498″. The Mil-P-21143/2- falls into the undersized category.
- Important note: All pin options may not be available in all sizes and materials.
- OEM branded pins have their own tolerances and specifications.
- Finally, the Oversized series of dowel pins are usually used to fit into worn holes and are generally used in the aftermarket for repairs. These pins are only available off the shelf in steel in a small range of sizes.
5. Can I specify if I need radius or chamfer on the pin ends?
The pin style will depend upon the spec and the material. Precision dowel pins may come with either a double chamfer or a radius on one end and a chamfer on the other end. Specific style requirements are available for special order and usually involve a lead time.
6. What information do I need to request a quote?
The easiest way to order is by either the manufacturer or MIL-SPEC part number. To order by description, you need the diameter, length and material and if applicable, and any special tolerance, plating or style requirements.
7. Do I need to buy special installation tools?
Just remember, no hammers! When installing dowel pins, never drive the pin into the hole with force. Always press it in for best results. And production favors pins since they require no extra fastening hardware for insertion, no secondary operations, and no mating parts. This ease-of-use adds up to speedier production, which makes everyone in the food chain happy!
8. What level of certification is required?
Generally, a Certificate of Conformance or a COC is sufficient for your customer. Full certification with material certs and test reports are often available for USA made and MIL-SPEC parts and might have an additional fee.
Available Dowel Pins Categories
We are Dowel Pin experts, offering the full catalog of standard Dowel Pins in Inch, Metric, Military and OEM branded options in a wide selection of materials, sizes and specifications. As stocking distributors, many dowel pins are available and ready to ship today from our national distribution centers.
- The full range of commercial and MIL-SPEC parts (M21143, MS16555, MS9390), including parts that are USA made, DFARS and ROHS compliant.
- Inch sizes to ASME ANSI B18.8.2 standards in Alloy Steel, Stainless Steel 18-8, 316, 400 Series and Hardened
- Metric sizes including DIN 7, DIN 6325, and ISO 2338 and 8734 in Alloy Steel, A2 & A4 Stainless Steel
- Precision Series and OEM branded equivalents to PIC, BERG, both Inch & Metric Precision Dowel pins including Press-Fit A, B and Slip-Fit C series and all MD series pins in 416 and 303 Stainless Steel.
In addition to our vast selections of standards, we offer Custom-made parts per print in non-standard sizes and exotic materials and finishes made here in the USA with full certifications. Minimums and lead times will apply.
Seeking parts not listed for purchase on our website? We’ve got you covered! Submit your Dowel Pin RFQ and our team of experts will return your quote quickly!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
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The Buyer’s Guide to Dowel Pins You Must Have Today!
Posted: August 26, 2022 Filed under: dowel pin, Mil-Spec, MS16555, MS16556 and Mil-P-21143., PRECISION DOWEL PIN Leave a commentMF Supply is a trusted Supplier of Precision Dowel Pins to manufacturers with our extensive assortment of Inch, Metric, Commercial, Mil-Spec and OEM brand names and equivalents.
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Buyer’s Guide to Metric Dowel Pins
Posted: April 3, 2018 Filed under: DIN 6325, DIN 7, dowel pin, ISO 2338, ISO 8734, Metric Dowel Pins, Mil-Spec, PRECISION DOWEL PIN Leave a comment7 Things to Know When Buying Metric Dowel Pins
This guide is a follow up to our Dowel Pin Buyer’s Guide. This post is specifically written to share with you the available options when it comes to procuring precision Metric dowel pins.
Our goal is to help simplify the buying process and guide you in the critical selection factors for this sometimes complex and confusing category of fasteners.
1. What standards are Metric Dowel Pins made to?
Metric dowel pins are tricky because they fall into two buckets:
- DIN / ISO standard – These metric Dowel pins are readily available in the commercial marketplace and in addition to your suppliers, can be procured through national catalogers like Mcmaster-Carr, Grainger and Holo-Krome. They come on steel and stainless steel.
- Precision Metric Dowel Pins – These “Precision” dowel pins are manufactured by precision component brands such as Pic Design, WM Berg and Unicorp who have their own technical specifications and are not governed by DIN or ISO standards. They are usually only offered in stainless steel through distributors of precision components.
2 . What are the specific criteria I can select for Metric dowel pins?
Here is a list of the criteria and available options available:
- Size
- Material
- Hardened or Unhardened
- End style
- Tolerances
3 . Can you list the standard and precision dowel pins available off the shelf?
- DIN 7
- DIN 6325 & DIN 6325H
- ISO 2338A & ISO 2338B
- ISO 8734
- PRECISION UNHARDENED PRESS FIT DOWEL PINS SS303
- PRECISION HARDENED DOWEL PINS SS416
4. Which types of metric dowel pins are available in which sizes and materials?
Use this handy grid to understand the sizes and materials available in each Metric dowel pin style.
Standard |
Ends |
Materials |
Tolerances / Fit |
Hardness |
Diameters |
DIN7ISO 2338ISO 2338A |
Rounded or beveled |
Steel (least common)300 Series Stainless Steel includingA1=18-8, 303, 304A4=316 |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M.8-M20 |
ISO 2338B |
Rounded or beveled |
300 Series Stainless SteelA1=18-8, 303, 304 |
H8 diameter tolerance |
Unhardened |
M1.5-10 |
DIN 6325DIN 6325HISO 8734AISO 8734 |
Rounded on one endBeveled on one end |
Alloy Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 52-62 |
M1-M25 |
Precision Unhardened |
Rounded |
300 Series Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M1-M12 |
Precision Hardened |
Rounded on one endBeveled on one end |
416 Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 36-42 |
M2-M10 |
Important note: All pin options may not be available in all sizes and materials.
5. When ordering, do I need to specify the dowel pin tolerance or call out attributes such as standard, undersized or oversized fit?
Metric dowel pins can show up under DINs and ISO numbers, including : DIN 7, DIN 6325, and ISO 2338 and 8734. When ordering DIN/ISO dowel pins it is best to include the Diameter, Length, Material, DIN or ISO and tolerance. For non DIN/ISO Precision metric dowel pins, you can order by the manufacturer part number, such as Pic (MDP series), WM Berg (DM Series), or Holo-Krome.
6. Can I specify if I need radius (round) or chamfer (bevel) on the pin ends?
The pin style will depend upon the spec and the material. Precision dowel pins may come with either a double chamfer, double radius, or a radius on one end and a chamfer on the other end. Check with the handy grid above for guidance.
Important note: The configuration of the ends of unhardened metric dowel pins are at the discretion of the manufacturer. If you have a specific style requirements, you might need to special order which usually involves a minimum and a lead time.
7. What if I need domestic or DFAR certified Metric dowel pins?
If you are ordering by a Precision Manufacturer part number, you are in luck! Most of the stainless steel pins produced by Pic, WM Berg and Unicorp qualify as DFAR compliant and full certifications with material certs and test reports are often available for USA made parts for a fee.
Metric Dowel Pins at MF Supply
We offer:
- The full range of commercial Metric Dowel pins including parts that are USA made, DFARS and ROHS compliant.
- Metric sizes including ASME ANSI B18.8.2, DIN 7, DIN 6325, and ISO 2338 and 8734
- Metric Precision Dowel pins including Press-Fit Series and all MD series pins in 416 and 303 Stainless Steel.
- Brand names and generic equivalents.
- Custom-made parts per print in non-standard sizes and exotic materials and finishes.
For more detailed information about Metric Dowel Pins, to request a line card, or to send an RFQ, visit our website. And if you don’t see what you need listed, as always, ask us. “Finding the right screw for you” is our tag line after all!
Contact me at robin@mfsupply.com with your questions, comments or helpful hints!
About Us
For more than 40 years, MF Supply has helped American manufacturers streamline operations, saving them time and money with our sourcing expertise and unique supply chain strategies. We are a WBE/WOSB certified stocking distributor of fasteners and electronic components.
We work with the best-established factories in the United States and DFARS-certified countries, and stock a huge inventory including all major brands and equivalents. MF Supply provides solutions including: same-day drop ship direct from the factory; custom sizes, materials and plating options; and DFARS parts with full paperwork and Certificates of Conformance.
We creatively solve common problems including hard-to-find parts and long lead times. Our sourcing and reworking expertise includes fast turnaround for modification of existing parts, hard to find standards and specials, special threads, non-standard diameters and lengths, exotic materials, special platings and short runs. We provide functional equivalents to expensive brand name fasteners and help our customers save money while reducing lead times.
Follow our blog at http://blog.mfsupply.com/
Buyer’s Guide for Using Functional Equivalents to OEM Brands
Posted: July 28, 2017 Filed under: Brand equivalents, keensert, key-locking inserts, Mil-Spec, POP Rivet, PRECISION DOWEL PIN, Precision Shoulder Screws Leave a comment5 Things to Know when Comparing Fastener Brands to Generic Alternatives
This year, we’ve discussed how the trademarked brand Keensert® is often available as a Mil-Spec or generic branded key-locking insert. We also reviewed how national brands of precision shoulder screws, such as Amatom, Concord, RAF and others are also offered by McMaster-Carr (tight tolerance series), MSC, Grainger and generically.
But how exactly do you determine which categories of fasteners cross to generic alternatives? This guide offers creative solutions including when to cross, and how to save money and reduce long lead times by using brand alternatives.
1. What is a functional equivalent when it comes to fasteners and precision components?
You can find hundreds of registered trademark-branded fasteners and components in the industrial marketplace. Much like brand-name pharmaceuticals such as Tylenol and Advil are available generically (as acetaminophen and ibuprofen), some brand name fasteners are also available as “generics,” “crosses,” “alternatives” or “functional equivalents.”
In the world of fasteners, a functional equivalent fastener is a part that is the same as the brand-name product in form, fit and function, including material and plating specifications.
2. How can I determine if I must use the brand name or if I can cross to a generic part?
Before you shop, check the bill of materials to see if it specifically calls out a particular brand name along with the part number. If no specific manufacturer’s name is listed, then you can typically use a functional equivalent.
Use this handy 4 point checklist as your guide:
- Does your bill of materials specifically call for the OEM brand-name fastener or component?
- Can you live with the lead time or will having parts sooner improve delivery of the final product?
- Will your supplier provide a certificate of conformance?
- Will saving money help you be more competitive?
3. What categories of fasteners are available as generic or functional equivalents?
Popular categories include adhesives and sealants, anchors, bits and nutsetters, cage nuts, flex type lock nuts, handles, Keenserts, knurled thumb screws, nylon insert stop nuts, precision shoulder screws, retaining rings, rivets & blind threaded inserts, self-clinching, fasteners, spacers and standoffs, speed clips, spring nuts, weld nuts, weld studs, and woodworking screws.
4. What brands of fasteners should I consider crossing to their generic or functional equivalent?
A sample list of brands that have generic alternatives:
3 STAR RIVETS USA, ABBATRON®, ALCOA, AMATOM®, APEX®, ARCONIC®, ATLAS®, AVDEL®, AVK®, B. F. GOODRICH, BOLLHOFF, BUCKEYE, CAPTIVE, CELUS®, CHERRY®, CONCORD, FASTENAL, GESIPA®, GRIPCO®, GLOBE ELECTRONICS, H. H. SMITH, HUCK, INDUX, INTERFAST, KEYSTONE, LOCTITE®, LYN-TRON, MACLEANESNA®, MARSON®, MCMASTER-CARR, MISUMI, MSC INDUSTRIAL, PEM®, PIC DESIGN®, POP®, POWERS®, QUICKSCREWS, RAF, RED HEAD®, ROTOR CLIP®, SHEREX, SIMPSON, SOUTHCO®, SPS TECHNOLOGIES, TINNERMAN®, U. S. ANCHOR. VIP, W. M. BERG, W. W. GRAINGER, WALDES TRUARC®.
5. What are the advantages of using functional equivalents?
Brand names are great, and when they are in stock, available and required by your customer, then you can buy them with confidence in their quality. However, one surefire way to save money and shorten delivery time is to cross the OEM brand part on your bill of materials to a functional equivalent.
Brands and Functional Equivalents at MF Supply
Supplying a full range of fastener products and services, MF Supply is an authorized distributor of Amatom/Carey, Captive (Pem equivalent), Chrislynn Inserts, Concord, EZ-Lok, Lok-mor, Lyn-tron, Microplastics, Shear-loc, S&M Retaining Rings, and Unicorp, as well as a distribution partner for many others. We have an expertise in dowel pins, inserts and Keenserts and domestic and Mil-Spec products.
We provide functional equivalents to expensive brand name fasteners and help our customers save money while reducing long lead times. Check out our recent case study where a functional equivalent was substituted for an OEM brand, reducing costs by 37% and shaving lead time. This time and money savings gave the manufacturer an advantage over their competition, which helped them win the job.
For more detailed information about brands we commonly cross, visit our website. And if you don’t see it listed, as always, ask us. “Finding the right screw for you” is our tag line after all!
MF Supply is a WBE/WOSB certified stocking distributor of precision fasteners and electronic components, specializing in precision hardware including precision shoulder screws. For more than 40 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services.