Buyer’s Guide to Metric Dowel Pins Refreshed for 2023!

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:

  1. 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.
  2. 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?

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.

Tolerances / Fit
ISO 2338
ISO 2338A
Rounded or beveled 
Steel (least common)
300 Series Stainless Steel including
A1=18-8, 303, 304
M6 diameter tolerance
Slightly Oversized
aka Press Fit
ISO 2338B
Rounded or beveled
300 Series Stainless Steel
A1=18-8, 303, 304
H8 diameter tolerance
DIN 6325
DIN 6325H
ISO 8734A
ISO 8734
Rounded on one end
Beveled on one end
Alloy Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Hardened to
RHC 52-62
Precision Unhardened
300 Series Stainless Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Precision Hardened
Rounded on one end
Beveled on one end
416 Stainless Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Hardened to
RHC 36-42

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!

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.

MF Supply Work With Us

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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