Carbon Steel Key-Locking Inserts (AKA Keenserts®) at www.mfsupply.com

MF Supply is an expert and industry leader when it comes to key-locking inserts, commonly known by the popular brand name Keensert®. We stock and source key-locking inserts in a wide variety of materials, platings and sizes, including Inch, Metric, Commercial and Mil-Spec options.

In today’s blog, we will showcase a comprehensive overview of Carbon Steel Key-Locking Inserts, covering their benefits, uses, styles, standards, sizes, and comparison with other key-locking inserts made from other materials — so you are all set before jumping off to procure them for your next project.

What are Carbon Steel Key-Locking Inserts?

Carbon Steel Key-Locking Inserts, often referred to in industry vernacular as Carbon Steel Keenserts®, are precision-engineered threaded inserts predominantly fabricated from high-grade carbon steel.

Featuring both internal and external threads, these inserts are adept at providing wear-resistant thread interfaces in substrates that are inherently susceptible to thread degradation or are insufficiently robust for the intended mechanical loads. The external threading of these inserts exhibits a larger diameter and pitch compared to the internal threads, ensuring a secure engagement with the parent material.

These components are specifically designed for thread reinforcement and repair applications across a broad spectrum of parent materials. Their key-locking mechanism involves the deployment of keys integrated into the insert body. Upon installation into a pre-tapped hole, these keys are driven outward into the parent material, thereby affording a secure mechanical lock that resists rotational and axial forces. Hence, this feature is pivotal in applications where vibrational loads or cyclic stresses are prevalent.

The versatility of Carbon Steel Key-Locking Inserts makes them beneficial for any sector requiring durable, reliable threaded connections, especially where materials are subject to wear, high stress, or require thread repair and reinforcement.

What Styles, Standards & Sizes Are Available?

Carbon Steel Keenserts®, or Key-Locking Inserts, have different styles in order to cater to a wide range of application requirements and material conditions. The distinct styles are designed to address specific challenges such as load capacity, space constraints, installation requirements, and the physical properties of the base material. Below is a list of all the styles available for these Key-Locking Inserts:

• Thin Wall | RKKA | KNM: These are used when minimal space is available or in applications where less material needs to be removed. They offer a good balance between strength and size. Available off the shelf in Internal Thread 10-24 through 1/2-20 and Metric M5-M12. Often referred to by their original Fairchild part numbers: RKKA
• Heavy Duty | RKK | KNHM: Designed for higher strength and durability, these are suitable for applications subject to high stress or where a stronger thread is required. Available off the shelf in Internal Thread 8-32 through 1-1/2, and Metric M4-M24. Often referred to by their original Fairchild part numbers: RKK
• Extra Heavy Duty | KNHXH: These inserts are used in extremely demanding applications where very high pull-out and torque resistance is needed. Available off the shelf in Internal Thread 6-32 through 1-12. No standard Metric option available. Often referred to by their original Fairchild part numbers: KNHXH
• Solid | KNJ: Unlike other types have both internal and external thread, solid inserts have only external thread. Once installed, they can be drilled and tapped as required. These solid inserts can be used to relocate misplaced holes, customize the internal threads, or plug existing holes.  They are extremely durable but might require more installation space. Available off the shelf in External Thread 3/8-16 through 1-1/4 and Metric M8-M32. Often referred to by their original Fairchild part numbers: KNJ.

Commonly available in diameters from 6-32 through 1-1/2, Carbon Steel Key-Locking Inserts can be used in a wide range of applications from small electronics to heavy machinery. The thread pitch varies accordingly, with finer pitches for delicate applications and coarser pitches for heavy-duty applications.

Carbon Steel Key-locking inserts are generally offered as commercial parts, and don’t have a Mil-Spec equivalent. They come standard with a phosphate finish.

*Note – Carbon Steel Key-locking Inserts do not come with a Self-Locking option, which is a standard option with Stainless Steel Keenserts®.

The Carbon Steel Difference!

How do Carbon Steel Key-Locking Inserts stack up against other materials? Here’s the breakdown:

• Stainless Steel: Stainless Steel Keenserts® are known for their corrosion resistance, especially in marine and chemical environments. However, Carbon Steel Key-Locking Inserts are generally stronger and more wear-resistant, which is beneficial in applications where the primary concern is strength rather than exposure to corrosive elements.
• 4140 Alloy Steel: This is a high-carbon alloy steel that provides excellent wear resistance and strength. While 440 Alloy Steel Keenserts® offer superior hardness, Carbon Steel Key-Locking Inserts typically excel in toughness and are more ductile, making them less likely to crack under high stress.
• A286: A286 is an iron-nickel-chromium stainless steel alloy known for its high strength and corrosion resistance at elevated temperatures. Carbon Steel Key-Locking Inserts may not match the high-temperature performance but are significantly more cost-effective for applications where extreme temperatures are not a concern.
• Nitronic 60: This material provides excellent galling and wear resistance. While it is superior in environments where these factors are critical, Carbon Steel Key-Locking Inserts offer a better balance of strength and cost-efficiency for general-purpose use.
• Inconel: Known for its ability to withstand extreme temperatures and corrosion, Inconel is often used in high-temperature applications. Carbon Steel Key-Locking Inserts, on the other hand, are more widely used in applications where high temperature and corrosion are not as critical but where high strength and lower cost are important.

Hence, Carbon Steel Key-Locking Inserts offer an excellent balance of performance and value, making them a preferred choice for applications where the benefits of higher-cost, specialized materials are not required. They stand out for their strength, toughness, and cost-effectiveness, providing a reliable and affordable solution for thread reinforcement and repair.

Carbon Steel Key-Locking Inserts at MF Supply!

MF Supply is a WBE/WOSB certified business, and a leading supplier of Carbon Steel Key-locking Inserts (AKA Keenserts®) for manufacturers, government and industry. At MF Supply, we understand the dynamic needs of the industry, including the balance of price, quality, availability and certification paperwork. Ready to see how we can help you make a difference?

Visit our website or browse through the links provided below to discover the perfect Carbon Steel Key-Locking Inserts for your next project!

Inch Carbon Steel Key-locking Inserts:

• Miniature & Thin Wall Styles Series
• Heavy Duty & Thick Wall Style Series
• Extra Heavy Duty Style Series
• Solid Style Series

Metric Carbon Steel Key-locking Inserts:

• Miniature & Thin Wall Styles Series
• Heavy Duty & Thick Wall Style Series
• Solid Style Series

Note – Installation requires a drill bit, a standard tap, an installation tool, and a hammer. Feel free to ask us about Keensert® Kits available for many Carbon Steel sizes. Kits include a minimum of 2 inserts, a drill bit, a tap and an installation tool.

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. “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.

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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, with an expertise in inserts, military fasteners and stainless steel hardware.  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.