Inch & Metric Nitronic Keenserts® Now Available at www.mfsupply.com!

In the bustling world of manufacturing and engineering, where every component counts and the margin for error is slim, MF Supply recognizes the intricacy involved in sourcing materials that offer both superior performance and extended durability. This is where our friends, the Key-locking Inserts (AKA Keenserts®) become the stars of the show. Today, we’re turning the spotlight on an insert that’s been making waves in the industry: the Nitronic 60 Key-locking Insert!

If you’re on the quest for Key-locking Inserts that promise to elevate the integrity of your projects, you’re in the right place. Nitronic 60 key-locking Inserts are not just components; they’re your peace of mind molded into high-performance alloy.

Why Nitronic 60 Key-locking Inserts? The Vanguard of Resilience

Picture a material that laughs in the face of wear, shrugs off corrosion, and doesn’t flinch under high torque. That’s Nitronic 60 for you — an alloy steel that’s as tough as they come. Crafted from this robust alloy, Nitronic Key-locking Inserts boast unparalleled wear and galling resistance. For those of you constantly battling the wear and tear that comes with mechanical demands, these threaded inserts are your knights in shining armor. Think of them as the silent guardians against the everyday wear-and-tear that can compromise your work.

The Rust Doesn’t Sleep, But You Can

Corrosion is the arch-nemesis of metal, lurking and waiting to undermine your structures. But with Nitronic 60’s exceptional corrosion resistance, rest easy knowing that your components are as steadfast as your ambition. Whether it’s the salty bath of marine environments or the demanding conditions of chemical processing, they’ve got you covered.

Strength That Speaks Volumes

Nitronic 60 Key-locking Inserts don’t just resist wear; they embrace strength. High stress, high torque — bring it on! The formidable might of Nitronic 60 makes these Key-locking Inserts the backbone for applications that can’t afford to falter, from the aerospace zeniths to the depths of automotive innovation.

The Nitronic 60 Difference

We hear you asking, “But how do they stack up against other materials?” Here’s the deal:

Nitronic 60, as a material, is a high-performance stainless steel alloy known for its excellent strength and resistance to wear and galling. This versatile alloy provides exceptional resistance to high temperature oxidation, crevice corrosion and general corrosion, making it well suited to marine and chemical applications. Key-locking inserts made from Nitronic 60 are used in various applications where high strength and corrosion resistance are a must.

  • Carbon Steel Inserts: Compared to standard steel, Nitronic 60 offers superior resistance to corrosion and galling.
  • Stainless Steel Inserts: Among stainless steels, Nitronic 60 typically outperforms varieties such as 304 or 316 in wear resistance.
  • Inconel Inserts: Inconel excels in high-temperature applications but comes at a higher cost and greater machining difficulty than Nitronic 60.
  • 4140 Alloy Inserts: 4140 Alloy provides greater tensile strength and enhanced performance at high temperatures, although it falls short in corrosion resistance and often necessitates protective coatings. Nitronic 60 is better suited for applications involving friction at moderate temperatures.
  • A286 Inserts: A286 excels in high-temperature applications, maintaining higher strength at elevated temperatures, though it’s tougher to machine and more expensive than Nitronic 60.

A Spectrum of Possibilities

We’re not about “one-size-fits-all” because we know your engineering needs are as unique as your blueprints. That’s why we offer Key-locking Inserts in inch, mil-spec and metric sizes that are tailored to the scope and scale of your vision — common internal diameters include #2-56 through 1 1/2-6 for inch & mil-spec sizes, and M2 through M24 for metric sizes. And with varying lengths at your disposal, the only limit is the application and your imagination. Materials

Compliance with stringent industry standards is not just a promise; it’s our practice. Our inserts meet or exceed critical aerospace and military specifications, ensuring that they deliver in applications where there is no room for error. Standards available include MS51830, MS51831, MS51832, NAS1394 and NAS1395. Series available include Miniature KNC, Thin Wall KN & KNM, heavy-duty KNH & KNHM, and extra heavy-duty series KNHXH.

Whether you’re in aerospace, automotive, defense, or any field that demands unyielding materials, these inserts are ready to serve. They’re the go-to for applications that require repeated assembly and disassembly, ensuring longevity and reliability every step of the way.

Discover More, Achieve More

MF Supply is a WBE/WOSB certified business, and a trusted supplier of Nitronic 60 Key-locking Inserts (AKA Keenserts®) for manufacturers, government and industry. Eager to delve deeper into the world of Nitronic 60 Key-locking Inserts? Visit our website, where innovation is just a click away, and join the ranks of manufacturers and engineers who don’t just build, but inspire.

With Nitronic 60 Key-locking Inserts, it’s not just about holding things together; it’s about unlocking possibilities. Discover the sizes, standards, and the success that our inserts can enable.

Inch & Mil-Spec Nitronic 60 Key-locking Inserts

Metric Nitronic 60 Key-locking Inserts

Do you still have questions or would like to speak with a representative? Reach out to us, and our MF Supply team of sourcing experts will help you find what you’re looking for. “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 and specialize in hard to find parts. We offer custom manufacturing and reworking solutions at competitive pricing, 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. 


“Heli-coils®” vs. “Keenserts®”: 3 differences you must know-Part 2 of 2

Welcome back to the second part of, “Heli-coils®” vs. “Keenserts®”: 3 differences you must know. As a refresher, both Helical Wire Inserts (AKA Heli-coils®) & Key-locking Inserts (AKA Keenserts®) are popular threaded inserts that are commonly used in precision manufacturing, transportation, and aerospace applications. Their uses overlap range from restoring/repairing stripped threaded holes, strengthening threaded holes in metals and other soft materials, providing high resistance to torque-out and pull-out, & to place threaded holes on materials too thin to accept them. The three main differences between Wire Inserts and Key-Locking Inserts lie in their strength, ease of installation & price. Today we will continue on from where we left of on our previous blog, and discuss about OEM brands, Mil-spec options, and how to order them!

Threaded Inserts’ Brands & Equivalents

A Helical Wire Insert, commonly known as “threaded wire insert,” is essentially a coil-wire made of stainless steel or other materials which, when installed, provide a new threaded hole surface. One of the most recognized brands for helical inserts is “Heli-Coil®,” but there are several others as well, including E-Z Lok, Bollhoff, Recoil, KATO, Perma-Coil, V-Coil and Time-Sert. Below is a list of some of the most well known brands for this category:

  • Heli-Coil®: Part of the Stanley Engineered Fastening brand, Heli-coil’s name is nearly synonymous with threaded wire inserts, and Heli-coil®is a registered trademark of Emhart® Teknologies, Inc.
  • Recoil®: Part of Howmet’s (previously Arconic, formerly Alcoa Fastening Systems) wire thread insert offering. Recoil offers helical wire inserts in bulk, replacement packets, kits and associated tools, taps and drill bits.
  • E-Z Lok®: Offering Wire Inserts under the E-Z Coil™ Helical Coil Insert brand, specializing in industrial and automotive .
  • KATO®: The Original Inventor & Manufacturer of the Bi-Directional Tangless Insert.

A Key-locking Threaded Insert, commonly known by the popular brand name “Keensert® and Keysert®,” is a solid bushing style threaded insert with unique external keys that get hammered into grooves through the threads—permanently locking the insert in place. Key-locking inserts are specifically designed for high-stress applications where strong, permanent threads are essential. Key-locking inserts offer exceptional resistance to vibration, torque-out and pull-out, making them suitable for critical components and assemblies that require a secure, immovable joint, or in scenarios where frequent assembly and disassembly might weaken the primary thread strength of the base material. While “Keensert®” is a trademarked name, tens of manufacturers and brands offer similar products in the solid threaded insert category including Acme, Camloc, Chrislynn, Clarendon, Fairchild, Loksert, Kaynar, Microdot and Tridair brands. Here is a list of the most popular brands:

  • Keensert®: is a registered trademark of Huck Patents, Inc. The trademark name is currently owned by the company that started it all, Howmet (formerly Arconic & Alcoa Fastening Systems).
  • Recoil®: The trademarked Keysert name belongs to Recoil, which is also part of the current Howmet family (formerly Arconic & Alcoa Fastening Systems).
  • Carr-Lane: Specializing in Tooling Components, Carr-Lane offers a large selection of Inch and Metric Key-locking inserts in steel and stainless steel.
  • Fairchild Fasteners®: Purchased by Arconic in 2002, Many original Fairchild part numbers are still produced and commonly used in the aerospace industry.
  • Acme – USA based manufacturers of inch, metric, Industrial Style and Mil-Spec key-locking inserts in a variety of materials and finishes.

Note: Various manufacturers and brands have their own designs, strengths, materials and applications for which they’re best suited. When choosing a threaded insert, it’s essential to consider factors like the material you’re working with, the stresses the insert will be under, and the expected lifecycle of the product. Industrial, automotive and aerospace industries each have their own requirements, which may include DFAR, First Article or other certifications. If you need assistance finding out what type of threaded insert is best suited for the project you’re working on, read part one of this blog, or reach out to us with your questions. MF Supply is an expert and leading supplier of Helical Wire Inserts and Key-locking Threaded Inserts—functional equivalents to top & expensive brands, such as Heli-Coil® & Keensert®.

Mil-Spec Options

Mil-spec Helical Wire Inserts (Heli-Coils®) are crafted to meet military specifications. They carry specific labels signifying their adherence to the rigorous standards established by the U.S. Department of Defense in order to guarantee that the inserts will fulfill the necessary requirements for military applications.

With that having been said, these threaded inserts often show up as free-running or self-locking inserts under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec Helical Wire Inserts’ series include MS122076 through MS124831, MA1565, MA3276, MA3277, MA3278, MA3279, MA3280, MA3281, MA3329, MA3330, MA3331, , MS21208, MS21209, MS33537, NA0276, NAS1130

Mil-Spec key-locking threaded inserts (Keenserts®) adhere to distinct mil-spec (military specification) series. Options for these inserts include Miniature, Thinwall & Lightweight, Heavy Duty, Extra Heavy Duty, Keylocking Inserts in Stainless Steel, A286, and 4140 Alloy materials. Here are several prevalent mil-spec series associated with them: MS51830, MS51831, MS51832, NAS1394, NAS1395, NA0146, NA0147, NA0148, NA0149, NA0150, NA0151. The mil-spec parts will often have a commercial equivalent that is also known under the original Fairchild nomenclature, including the KN, KNC, KNH, KNL & KNCL Series.

Authentic Mil-spec parts will be available with documentation that confirm their compliance to the specification. Examples of certified paperwork might include a Certificate of Conformance, material traceability, DFAR statement, and chemical and/or physical tests reports.

How to Order

Now you know the differences between Helical / Heli-coils® and Key-locking / Keensert® / Keyserts®, the brands available, and the mil-spec series options.

To find the exact insert you are seeking on our website, there are currently four ways to proceed:

1. You can visit the Keenserts®, Threaded Inserts & Helical Wire Inserts category section of our website, and choose between Keenserts® for Manufacturers or Helical Wire Inserts. Once you select the desired category of products, you can then narrow down your search by selecting between metric or inch & mil-spec sizes, materials, etc.

2. You can also visit our website and enter the product standard, product number or keyword (e.g., MS51830, MS51830-101, “Keenserts,” “Helical Inserts,” etc.) in our search bar, and click the “Search” button. Once the list of available products are listed, you may use our product filters to search for the desired size, material, etc.

3. Alternatively, you could also use our newly added Product Finder tool! Select the desired Item Type, Subtype, Material, etc. And when you’re done selecting, simply click on the “Search” button, and the product finder will display a list of available products for you. 

4. Lastly, you could also reach out to us or Request a Quote. Our MF Supply team of sourcing experts are here to assist you and help you find the right product(s).

Once you find the insert you need, you can request a quote or buy online.

Key-locking Inserts (Keenserts®) & Helical Wire Inserts (Heli-Coils®) at MF Supply

MF Supply is a WBE/WOSB woman owned business, and leading supplier of Keenserts® & Helical Wire Inserts including major OEM brands and brand equivalents, in imperial, metric and mil-spec sizes and materials.

We stock a huge inventory including Miniature, Thinwall, Lightweight, Heavy Duty, Extra Heavy Duty, Locking, Non-Locking, Solid and Floating style Keenserts® in a variety of sizes and materials. Our mil-spec and certified insert products are DFAR compliant with COC and full certifications available upon request.

We Invite You To Request a QuoteDownload a Guide or a Line Card Today!

Do you still have questions or would like to speak with a representative to request a quote? Reach out to us, and our MF Supply team of sourcing experts will help you find what you’re looking for. “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. 


“Heli-coils®” vs. “Keenserts®”: 3 differences you must know-Part 1 of 2 (Refreshed for 2023)

Today we will re-introduce you to our blog, “Heli-coils®” vs. “Keenserts®”: 3 differences you must know-Part 1 of 2, published back on 2020. We will compare these two fastener products that are used to repair damaged threads & threaded holes, or to strengthen/reinforce a weaker parent material like aluminum. Both Helical Wire Inserts & Key-locking Inserts are commonly used in precision manufacturing, transportation and aerospace applications. Their versatility, however, ensures their presence in nearly every industry that utilizes threaded fasteners.

What are the main uses of Threaded inserts?

Both “Heli-coil®” or Helical wire inserts and “Keensert®” or Key-locking inserts fall under the “Threaded Insert” category of fasteners.

Threaded insert, also known as a threaded bushing, is an insert that has internal threads, and is fastened into an object to add or reinforce a threaded hole.  Threaded inserts may be used to repair a stripped threaded hole, provide a durable threaded hole in a soft material, place a thread on a material too thin to accept it, mold or cast threads into a work piece thereby eliminating a machining operation, or simplify changeover from unified to metric threads or vice versa. Although Helical Wire inserts and Key-locking externally threaded inserts are used in similar ways, there are 3 main distinctions that we detail below. But first, let’s take a closer look at each of these fasteners:

What is a Helical Insert Wire Insert? (aka Heli-coil®)

Helical wire inserts are precision-formed continuous wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material. Often underestimated, the popular misconception is that Helical wire inserts are intended solely for thread repair, when, in fact, they have other significant uses.  Not to be confused with other types of threaded inserts or rivnuts, Helical wire inserts resemble springs and are sometimes referred to as “Screw Thread Inserts (STI)” ,“Helicals” or by the popular brand “Heli-Coil®” which is a registered trademark of Emhart® Teknologies, Inc.

Three typical applications for using Helical wire inserts are:

  • to repair damaged threads in parts that would otherwise have to be scrapped
  • to strengthen threads against failures due to stripping, seizing or corrosion
  • to convert threads between inch and metric sizes

What is a Key-locking insert? (aka Keensert® or Keysert®)

The Key-locking threaded insert is a solid bushing style insert that is threaded on both the inside and the outside and has wedges or “keys” attached to the top of the insert. These externally threaded inserts are used to distribute loads and repair or strengthen threads against failures due to stripping, seizing or corrosion. Key-locking inserts are commonly used in high torque and high temperature situations, and in applications where fasteners may be repeatedly removed and reassembled. Key-locking inserts are often referred to as Keenserts® and Keyserts®, which are registered trademarks for the most popular brand names for this part. (Keensert® is a registered trademark of Huck Patents, Inc. & Keysert® is a registered trademark of Alcoa Fastening Systems).

Typical applications are transmission housings, electronic equipment and suspension units. Key-locking inserts are commonly found in aerospace assemblies.

How do they work?

Helical wire inserts work because the diamond shaped helically formed wire coil screws into a threaded hole to form a mating internal thread for a screw or stud.  

Key-locking inserts are threaded into a pre-tapped hole, and then the keys are hammered into grooves through the threads, permanently locking the insert in place. Their “keys”, which are driven down into the tapped threads, provide a mechanical lock against rotation, especially when the mating stud or bolt will be removed frequently.

What materials, sizes and styles are available?

Key-locking Inserts/ Keenserts®

Key-locking inserts come in four main styles: Miniature, Thin Wall, Heavy Duty Wall (general purpose) and Extra Heavy Duty.

  • Miniature Key-locking inserts are used in electronic and aerospace applications where size and strength are critical. These inserts may be installed in sheet material as thin as 1/16″.
  • Thinwall inserts have smaller external threads than standard heavy-duty inserts and are ideal for tight spaces where less pull-out strength is acceptable.
  • Heavy Duty inserts have a thick, heavy-duty thread wall, suitable for most applications.
  • Extra-heavy duty inserts are used in oversized and overly worn holes.

Key-locking inserts can be internally self-locking or non-locking (the standard is non-locking and is sufficient for the most common applications).

Inserts with the internal self-locking feature are designed to securely lock a bolt when it is entered into the insert only a few turns. Even after repeated installations and removals of the bolt, the lock maintains sufficient locking torque to prevent the bolt from vibrating out.

Common Materials available include Carbon steel, Stainless Steel, Alloy 4140 and A286. Nitronic and other materials may be available with a lead time.

Internal Diameters available: American/Inch #2-56 to 1 ½-6 ” and Metric M2 to M24

Helical wire inserts / Heli-Coils®

Helical wire inserts come in 2 main styles: tanged and tangless (currently, MF Supply specializes in the tanged style).

The original and widely used tang style has a prong at one end to facilitate installation. The newer tangless style has no prongs to break off, retrieve, or lose. Tangless inserts are commonly used in electronic applications where loose tangs are might cause damage.

Helical wire inserts can be free-running or self-locking.

Free running is the most common style used for thread repair. The “free” diameter of the insert is larger than the installed diameter and this configuration generates balanced pressure distribution between the coils and threads.

Self-locking style inserts are recommended for applications that require constant torque, or are subject to stress or vibration. The locking style features a crimped turn that acts as a locking mechanism that grips the bolt or screw to prevent loosening from vibration, eliminating the need for lock wiring, lock-nuts, lockwashers, pellets/patches or other thread locking devices.

Common Materials available include Stainless Steel, Phosphorous Bronze, Inconel X-750 and Nitronic 60 and 90.

Internal Diameters available: American/Inch #2-56   to   1 ½-6” and and Metric M2   to   M24.  Standard inserts lengths measure from 1x to 3x the diameter. Note: larger sizes may be available by special order.

Why use a Key-locking insert vs. a Helical wire insert?

There are three main differences between Key-locking inserts and Helical wire inserts:

1) Strength: Key-locking inserts are stronger than Helical wire inserts

2) Ease of installation: Key-locking inserts are easier to install than Helical wire inserts

3) Price: Key-locking inserts are more expensive than Helical wire inserts!

So here is some direction on how to select the correct threaded insert for your application:  In heavy wear, high vibration and high heat situations where saving space is not a concern and hole depth is limited, Key-locking inserts are the best bet.

When reducing costs and minimizing space are priorities, Helical wire inserts are the way to go. They are particularly useful for creating permanent strong threads in softer materials such as aluminum, titanium and magnesium alloys, and are best suited to lower heat and lower torque environments.

Stay tuned for our next blog, where we discuss, brands and mil-spec options, how to order and installation options!

Key-locking Inserts (Keenserts®) & Helical Wire Inserts at MF Supply

MF Supply is a WBE/WOSB woman owned business, and a trusted supplier of Keenserts & Helical Wire Inserts for manufacturers, government and industry.

We Invite You To Request a Quote, Download a Guide or a Line Card Today!

  • Full ecommerce enabled website with technical manual available 24/7
  • Same day drop ship from factory for thousands of items.
  • Functional Equivalents to expensive brand name fasteners save money and reduce long lead times.
  • Creatively solve problems including hard to find parts and long lead times
  • WBE/WOSB Woman Owned Certified Small Business.

Do you still have questions or would like to speak with a representative to request a quote? Reach out to us, and our MF Supply team of sourcing experts will help you find what you’re looking for. “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. 


Get the Job Done with a Pneumatic Power Tool

Now introducing the Rock Solid Hydro-Pneumatic Key-locking Insert Installation Tool

A single button is all it takes to operate this tool and to get the job done. No need to use a hammer and a drill to drive the key locking insert into place. 

Don’t know what a pneumatic power tool is or how to use one? Read on!

What is a pneumatic power tool? 

Pneumatic tools are designed to speed up the installation process of key locking inserts—also known as keenserts. They provide you with increased precision and control, improved torqueing, reduced vibration and noise, and more versatility for your projects.  

How do I use a pneumatic power tool? 

Using a pneumatic power tool is very simple and bound to give you some peace of mind in the process! To use a pneumatic power tool, simply set up or prepare the material to be used in the key locking insert (Keensert) installation process and: 

  1. Drill and countersink the material. 
  1. Tap the hole in the material. 
  1. Insert the key locking insert (Keensert) into the hole. 
  1. Screw the key locking insert down into the material with the aid of the pneumatic power tool!  

Keensert Installation Tool Kit

We offer the pneumatic power tool you need to quickly assemble your key locking inserts. Check them out here. Request a quote today, and our team of experts can help source your needs! 

Do you need more details on why you need a pneumatic power tool? Watch the video below!  

Optionally, you might also be interested on reading our previous blog posts about pneumatic power tools, and on how to manually install key locking inserts (Keenserts)


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

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. 


What is the Difference Between a Keensert and a Helical Insert?

What is a Helical Inset?

A Helical wire insert is a spring-like precision form wire coil that provides a permanent thread that’s stronger than the parent material. They are also often called a screw thread insert or a Helical insert, but the popular brand name is Heli-Coil, a registered trademark of Emhart Teknologies.

What is a KeyLocking Insert?

A key-locking insert is a solid bushing style insert that is threaded on the inside and the outside with keys on the top. It’s commonly called a Keensert or Keysert, and these are the registered trademark names of Huck Patents and Alcoa Fastening Systems.

Why Would I Use a Helical Insert vs. a Keensert, and Vice Versa?

  • Strength: A key-locking insert is much stronger than a helical insert, particularly in high temperature and high torque environments.
  • Ease of Install: A key-locking insert is easier to install than a helical wire insert.
  • Price: A wire insert is much less expensive than a key-locking insert.

When Would I Use a Keensert?

In a heavy-ware, high vibration, high heat situation when you don’t need to save space and the whole depth is not a key consideration. The key-locking insert is the way to go.

When Would I Use a Helical Insert?

If you need to reduce costs, you’re minimizing space. The Helical wire insert is the way to go. They’re very useful for creating a permanent, strong thread and softer material like aluminum or titanium. And they’re best suited to the lower heat environments.

Learn more about the difference between key-locking inserts and helical wire inserts here!

Learn More About Keenserts vs. Helical Inserts

If you are interested in learning more about our Keensert and Helical Insert product offerings, contact us today! If you’re ready to place your order, check out our products here!


Keensert Installation Tool Kits

Keenserts are very small but very strong key locking inserts used across many industries, especially in aerospace and precision manufacturing. While Keenserts are easy to install, it is essential to have all of the necessary tools to properly install them.

What Hole Size and Tools do I Need to Install My Keenserts Manually?

This is a common question we receive from manufacturers, so today, we are going to share everything you need to know to install your key locking inserts.

Prior to installing a key locking insert, you have to check with the supplier to make sure you have the proper drill and tap. Each part number has its own combination of drill and tap. This is really important, and it’s based on the outside and inside diameter.

Check out our Keensert Buyer’s Guide, Keensert Cross-Reference Guides, and How to Manually Install Keenserts.

Commercial or Military Key Locking Inserts?

It’s also important to note that each key locking insert has different types of thread depending upon their military or commercial. So, prior to installing the inserts, you need to have the following information…

  • Nose assembly.
  • Drill and tap size for the insert you’re installing.
  • The fastener you’re installing.

Tools For Keensert Installation:

  • Drill
  • Drill Bit
  • Drill or Tap Wrench
  • Tap
  • Countersink Tool
  • Keensert Installation Tool
  • Hammer

What is a Broaching Tool, and When Will I Need One?

A broaching tool is an extra installation tool that is used for very hard parent materials such as A286 or A4140. The purpose of the broach is to create slots for the keys in the parent material when the regular tools won’t cut it.

Hydro-Pneumatic Keensert Installation Tool

If you are installing key locking inserts by the 1,000s, then the pneumatic tool is a better option for installation. Learn more here.

Learn More About Keensert Installation

If you would like to learn more about our key locking inserts or any of our other hardware products, continue to browse our website and contact us today!


Installing Key Locking Inserts with Pneumatic Power Tools

In last week’s blog, we discussed when and how to install key locking inserts manually. If you have a few hundred inserts to install, the manual process is fine. However, if you are installing these Keenserts by the thousands, then you will want to use a pneumatic power tool to speed up the processes.

How to Install Keenserts with a Pneumatic Tool

  • The beginning of the installation process is the same as a manual installation.
  • Drill and Countersink the Material
  • Tap the Material
  • Manually Insert the Key Locking Insert
  • The next step is to use the power tool to simply screw the key into place.

You can see how this process can save you so much valuable time if you are installing the key locking inserts by the thousands!

Keensert Installation Tool Kit

We offer the pneumatic power tool you need to quickly assemble your key locking inserts! Check them out here.

Learn More About MF Supply

MF Supply is your go-to for all of your hardware and safety needs! Continue to browse our website and contact us today if you would like to learn more!


How to Manually Install Key Locking Inserts

What is a Keensert?

A Keensert or key locking insert is a solid bushing style insert that is threaded on both the inside and the outside and has wedges or “keys” attached at the top. These inserts are used to distribute loads and repair or strengthen threads against failures due to stripping, seizing or corrosion. They are commonly used in precision manufacturing and aerospace applications.

Check out our Buyer’s Guide to Keenserts!

What is the Best Way to Install Keenserts?

There are a few methods used to install key locking inserts. Manual installation is best for assemblies that are in the hundreds, but if you are installing a lot of Keenserts, pneumatic installation is the way to go.

Keensert Manual Installation

  1. Drill and Countersink the Material
  2. Tap the Material
  3. Manually Insert the Key Locking Insert
  4. Use the Installation Tool to Drive the Keensert

Here is the full installation clip from the video.

Stay Tuned and Learn More

If you are interested in learning more about our hardware, check out our other blogs and browse our products online. If you would like to learn how to install Keenserts with pneumatic tools, stay tuned for next week’s blog!


Keenserts: Inch and MIL-SPEC Keylocking Inserts

What is a Keensert?

A Keensert is a small bushing style insert that is threaded both inside and out, with wedges or little keys that are attached to the top of the insert. This small piece of hardware is generally used to distribute loads and to strengthen or repair threads against failure due to stripping, seizing, or corrosion.

When is a Keensert Used?

They are used in environments that have a lot of vibration, torque, and even in high-temperature applications. They are also sometimes used in applications where a fastener has to be taken out, replaced, or it has to be reassembled.

What Size and Material Keenserts Does MF Supply Sell?

Our Keenserts come in a variety of sizes and materials; you can view our entire selection on our online store here.

Need to cross your part number to find the right Keensert for your needs? Use our Mil-Spec & Inch Keensert Cross Reference charts!

Why Choose MF Supply for Your Keenserts?

We specialize in the military version of Keenserts, so we carry the MS51830 series, which is an equivalent to the KN and KNC series. These are a high demand Keensert.

They come with full paperwork and traceability. The majority of those our Keensert are stainless steel, but you can get them in a variety of materials and sizes.

Another huge benefit is that we stop-limit our distribution centers around the country so we can drop ship them at a moment’s notice, so there is no delay.

Learn More About Fasteners from MF Supply

If you are looking for a quick and reliable fasteners distributor, MF Supply is a leading supplier of Inch & Mil-Spec keylocking inserts. Contact us today to learn more!


“Heli-coils” vs. “Keenserts”: 3 differences you must know-Part 1 of 2

Today we will compare 2 popular fastener products that are used to repair damaged threads or strengthen a weaker parent material like aluminum: Helical Wire Inserts and Key-locking Inserts.  Both are commonly used in precision manufacturing and aerospace applications.

What are the main uses of these threaded inserts?

Both “Heli-coil” or Helical wire inserts and “Keensert” or Key-locking inserts fall under the “Threaded Insert” category of fasteners. A threaded insert, also known as a threaded bushing, is a fastener element that is inserted into an object to add a threaded hole. They may be used to repair a stripped threaded hole, provide a durable threaded hole in a soft material, place a thread on a material too thin to accept it, mold or cast threads into a work piece thereby eliminating a machining operation, or simplify changeover from unified to metric threads or vice versa. Although Helical Wire inserts and Key-locking externally threaded inserts are used in similar ways, there are 3 main distinctions that we detail below. But first, let’s take a closer look at each of these fasteners:

What is a Helical Insert Wire Insert? (aka Heli-coil)

Helical wire inserts are precision-formed continuous wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material. Often underestimated, the popular misconception is that Helical wire inserts are intended solely for thread repair, when, in fact, they have other significant uses.  Not to be confused with other types of threaded inserts or rivnuts, Helical wire inserts resemble springs and are sometimes referred to as “Screw Thread Inserts (STI)” ,“Helicals” or by the popular brand “Heli-Coil” which is a registered trademark of Emhart® Teknologies, Inc.

Three typical applications for using Helical wire inserts are 1) to repair damaged threads in parts that would otherwise have to be scrapped; 2) to strengthen threads against failures due to stripping, seizing or corrosion; 3) to convert threads between inch and metric sizes.

What is a Key-locking insert? (aka Keensert or Keysert)

The Key-locking threaded insert is a solid bushing style insert that is threaded on both the inside and the outside and has wedges or “keys” attached to the top of the insert. These externally threaded inserts are used to distribute loads and repair or strengthen threads against failures due to stripping, seizing or corrosion. Key-locking inserts are commonly used in high torque and high temperature situations, and in applications where fasteners may be repeatedly removed and reassembled. Key-locking inserts are often referred to as Keenserts® and Keyserts, which are registered trademarks for the most popular brand names for this part. (Keensert® is a registered trademark of Huck Patents, Inc. & Keysert® is a registered trademark of Alcoa Fastening Systems).

Typical applications are transmission housings, electronic equipment and suspension units. Key-locking inserts are commonly found in aerospace assemblies.

How do they work?

Helical wire inserts work because the diamond shaped helically formed wire coil screws into a threaded hole to form a mating internal thread for a screw or stud.  

Key-locking inserts are threaded into a pre-tapped hole, and then the keys are hammered into grooves through the threads, permanently locking the insert in place. Their “keys”, which are driven down into the tapped threads, provide a mechanical lock against rotation, especially when the mating stud or bolt will be removed frequently.

What materials, sizes and styles are available?

Keenserts

Key-locking inserts come in four main styles: Miniature, Thin Wall, Heavy Duty Wall (general purpose) and Extra Heavy Duty.

  • Miniature Key-locking inserts are used in electronic and aerospace applications where size and strength are critical. These inserts may be installed in sheet material as thin as 1/16″.
  • Thinwall inserts have smaller external threads than standard heavy-duty inserts and are ideal for tight spaces where less pull-out strength is acceptable.
  • Heavy Duty inserts have a thick, heavy-duty thread wall, suitable for most applications.
  • Extra-heavy duty inserts are used in oversized and overly worn holes.

Key-locking inserts can be internally self-locking or non-locking (the standard is non-locking and is sufficient for the most common applications).

Inserts with the internal self-locking feature are designed to securely lock a bolt when it is entered into the insert only a few turns. Even after repeated installations and removals of the bolt, the lock maintains sufficient locking torque to prevent the bolt from vibrating out.

Common Materials available include Carbon steel, Stainless Steel, Alloy 4140 and A286.

Internal Diameters available: American/Inch #2-56   to   1 ½-6 ” and Metric M2 to M24

Helical wire inserts

Helical wire inserts come in 2 main styles: tanged and tangless (currently, MF Supply spcializes in the tanged style).

The original and widely used tang style has a prong at one end to facilitate installation. The newer tangless style has no prongs to break off, retrieve, or lose. Tangless inserts are commonly used in electronic applications where loose tangs are might cause damage.

Helical wire inserts can be free-running or locking.

Free running is the most common style used for thread repair. The “free” diameter of the insert is larger than the installed diameter and this configuration generates balanced pressure distribution between the coils and threads.

Locking style inserts are recommended for applications that require constant torque, or are subject to stress or vibration. The locking style features a crimped turn that acts as a locking mechanism that grips the bolt or screw to prevent loosening from vibration, eliminating the need for lock wiring, lock-nuts, lockwashers, pellets/patches or other thread locking devices.

Common Materials available include Stainless Steel, Phosphorous Bronze, Inconel X-750 and Nitronic 60 and 90.

Internal Diameters available: American/Inch #2-56   to   1 ½-6” and and Metric M2   to   M24.  Standard inserts lengths measure from 1x to 3x the diameter. Note: larger sizes may be available by special order.

Why use a Key-locking insert vs. a Helical wire insert?

There are three main differences between Key-locking inserts and Helical wire inserts:

1) Strength: Key-locking inserts are stronger than Helical wire inserts

2) Ease of installation: Key-locking inserts are easier to install than Helical wire inserts

3) Price: Key-locking inserts are more expensive than Helical wire inserts!

So here is some direction on how to select the correct threaded insert for your application:  In heavy wear, high vibration and high heat situations where saving space is not a concern and hole depth is limited, Key-locking inserts are the best bet.

When reducing costs and minimizing space are priorities, Helical wire inserts are the way to go. They are particularly useful for creating permanent strong threads in softer materials such as aluminum, titanium and magnesium alloys, and are best suited to lower heat and lower torque environments.

Stay tuned for our next blog, where we discuss, brands and mil-spec options, how to order and installation options.

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