Military-Grade Fasteners: Frequently Asked Questions*

Grade-BD Cap screws

Q: What type of steel are Kanebridge’s Grade-BD cap screws made from?

A: Per military requirements, the ASTM A354 Grade BD cap screws are made from medium carbon fine grain alloy steels that conform to the requirements of AISI alloy steels.

All of these materials are fine grained to provide the high levels of strength and toughness, which are required in these critical fasteners. Specific steel grades are chosen not only to meet the alloy steel requirements as listed in ASTM A354, but also to provide the required hardenability. This insures that the final product offers the correct mechanical properties to meet all military specifications.

Q: Do Kanebridge’s Grade-BD cap screws meet the revised ASTM B633 plating specification, including the heat-treating and baking requirements the standard specifies?

A: Yes. The ASTM B633 standard was revised in 2007.

One of the changes concerned the amount of time certain fasteners are baked to reduce the effects of hydrogen embrittlement. Prior to this revision, plated Grade-BD cap screws were required to be baked for at least 4 hours at a temperature of 190°C to 220°C. The new standard calls for these parts to be baked for at least 10 hours at 190°C to 220°C. All of our manufacturers meet this standard.

Q: There are special requirements for how promptly these parts are to be baked after plating. How can I assure my customers your Grade-BD cap screws meet these standards?

A: The requirements you refer to are also delineated in ASTM B633, section 6.5.

This section addresses post-plating treatment to reduce the effects of hydrogen embrittlement, specifically, the time gap between plating and baking. This treatment must be done within 4 hours of the electroplating operation. Rest assured—all of our manufacturers meet this standard.

Q: Are the finished Grade-BD cap screws ultimately tested for hydrogen embrittlement?

A: Yes. The testing performed is in accordance with ASTM F606, called the stress durability test.

Samples of plated fasteners are placed in a static load fixture with a wedge fixture under the head, and the fastener is loaded to 75% of the ultimate tensile strength. The fastener is left with this load for 48 hours. If the assembly has not failed, it is disassembled and examined for any evidence of embrittlement. The test specimens are visually examined under a minimum of 10 times optical magnification.

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QSLD-Approval

Q: What does QSLD-approval mean?

A: On the Qualified Suppliers List for Distributors

The Defense Supply Center Philadelphia (DSCP) has a Qualified Suppliers List for Distributors (QSLD) for Class 2 Threaded Fasteners identifying pre-qualified sources for certain products purchased by DSCP. Distributors on this list are recognized by DSCP as meeting all necessary criteria, particularly regarding quality control, to sell specified fasteners that are ultimately sold to DSCP. Since August 17, 2006 Kanebridge is approved by DSCP as having met all of the requirements to be such a distributor.

This means any military-grade parts sold from Kanebridge’s Elgin, Illinois facility, that were purchased from and made by a QSLM-approved manufacturer can be purchased by another distributor on the QSLD-Approved list for resale to DSCP.

If you are a QSLD-Approved distributor, congratulations! Kanebridge completes the chain of distribution that gives you a reliable source for fully certified, military-grade hardware that ships the same day.

QSLD-Approved INventory

Q: What Kanebridge items are QSLD-approved?

A: The following items are purchased from QSLM-Approved manufacturers:

• ASME B18.2.1 Grade-BD Hex Cap Screws
• MS16997 Socket Head Cap screws
• MS24693 Phillips 100° Flat Machine Screws
• MS35206 Phillips Pan Coarse Machine Screws
• MS35207 Phillips Pan Fine Machine Screws
• MS35307 Coarse Hex Cap Screws, 300 Series Stainless
• MS35275 Drilled Fillister Coarse Machine Screws, 300-series SS
• MS35276 Drilled Fillister Fine Machine Screws, 300-series SS
• MS35308 Hex Cap Screws, Fine, 300 Series Stainless
• MS51957 Phillips Pan Coarse Machine Screws, 18-8
• MS51957 Phillips Pan Coarse Machine Screws, Black Ox over 18-8
• MS51958 Phillips Pan Fine Machine Screws, 18-8
• MS51958 Phillips Pan Fine Machine Screws, Black Ox over 18-8
• MS51959 Phillips 82° Flat Coarse Machine Screws, 18-8
• MS51960 Phillips 82° Flat Fine Machine Screws, 18-8
• MS51967B Finished Hex Nut, Coarse, Grade B, Cadmium Yellow
• MS51967C Finished Hex Nut, Coarse, Grade C, Cadmium Yellow
• NAS 1351 Socket Cap Screws-Fine thread, SS
• NAS 1352 Socket Cap Screws-Coarse thread, SS

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military certifications

Q: Do the certifications you furnish include the mil-spec part numbers?

A: Yes

All of our military certifications include the applicable military part number, including the ASME part numbers for all Grade BD high alloy hex cap screws. Kanebridge furnishes these certifications at no charge and can also be downloaded from your invoices on FasNet.

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DFARS-Compliance

Q: I am getting more requests for military parts that are “DFARS-compliant.” Are Kanebridge’s military parts DFARS-compliant?

A: DFARS-compliance pertains to any fasteners made from specialty steel or high alloy steel. This definition includes all stainless steel parts and all Grade-BD parts. All of the military fasteners sold by Kanebridge that are stainless or alloy steels are DFARS-compliant.

Furthermore, all of the MS90725 and MS90726 Grade-5 cap screws sold by Kanebridge are DFARS-compliant. Grade-5’s are subject to DFARS regulations if made from steel with a Chromium content of 0.26% or greater. All of the MS90725 and MS90726 Grade-5 cap screws that Kanebridge sells are manufactured from 4037M steel. This steel has a Chromium content of 0.27%. Therefore, these parts are subject to DFARS-compliance.