At Wilson-Garner, we manufacture a long list of specialty fasteners, which are used for a variety of industrial applications. One category of these specialty fasteners is MS fasteners.

Not sure what those are, or just looking for some more information on them? We’ve got you covered. Below, we’ll discuss what MS fasteners are, a few of their specifications, and the experience our team has working with them.

What Are MS Fasteners?

To understand what MS fasteners are, it’s first important to understand the acronyms and abbreviations associated with their name. “MS” is short for “mil-spec,” which is short for “military specification.”

MS fasteners, or mil-spec fasteners, are fasteners that are designed and maintained by the United States Military. They must meet certain strength, durability, and safety standards set by the U.S. Department of Defense.

Originally, MS fasteners were produced for specific military applications like heavy-duty vehicles, naval vessels, and aircraft equipment. They were used on products held to a higher standard than commercial products, due to their importance in high-stakes projects and situations. These fasteners were designed with specific features that allowed them to function under extreme conditions because the consequences would be catastrophic if they were to malfunction.

However, as years passed, manufacturers in other industries recognized that these highly durable fasteners could benefit a number of non-military applications as well. So, today, you’ll find MS fasteners to be more widely used, especially for things like bridges, large structures, sports cars, drones, and commercial planes and ships.

RELATED: Need a specialty bolt, screw, or stud? Wilson-Garner can help.

4 Common Mil-Specs

To better understand what these mil-specs include, let’s run through a few examples of some of the most common ones we feature at Wilson-Garner: MS35764, MS90725, MS18153, and MS35355.

MS35764

MS35764 is the mil-spec for SAE J429 Grade 8 Place bolts. It states that an MS Grade 8 Place bolts must meet the following requirements:

  • Material: Steel
  • Surface Treatment: Cadmium plating or zinc phosphate coating
  • Head Marking: Marked on top with manufacturer’s identification and the number 8 (for Grade 8 material)
  • Minimum Tensile Strength: 150,000 psi

MS90725

MS90725 is the mil-spec for SAE Grade 5 hex head cap screws. It states that an MS Grade 5 hex head cap screw must meet the following requirements:

  • Material: Steel
  • Surface Treatment: Cadmium plating or chromate coating
  • Head Marking: Marked on top with manufacturer’s identification and three radial lines to signify Grade 5 material
  • Minimum Tensile Strength: 120,000 psi

MS18153

MS18153 is the mil-spec for SAE Grade 8 hex head cap screws with a drilled head. It states that an MS Grade 8 hex head cap screw with a drilled head must meet the following requirements:

  • Material: Steel
  • Surface Treatment: Zinc coating
  • Head Marking: Marked on top with manufacturer’s identification and the number 8 (for Grade 8 material)
  • Minimum Tensile Strength: 120,000 psi

MS35355

MS35355 is the mil-spec for machine bolts with square heads. It states that an MS machine bolt with a square head must meet the following requirements:

  • Material: Steel
  • Surface Treatment: Cadmium or zinc plating
  • Head Marking: Marked on top with manufacturer’s identification
  • Minimum Tensile Strength: 55,000 psi

Wilson-Garner’s Work with MS Fasteners

Wilson-Garner’s work with MS fasteners dates back to 1967. This is the year our patented asymmetric Place bolt was approved for use by the U.S. Department of Defense. From there, we earned ourselves a spot on the Qualified Supplier List for Manufacturers (QSLM) by the Defense Logistics Agency (DLA). We’ve also become a Subsafe Level 1 approved supplier to the U.S. Navy and an ISO 9001:2016 certified manufacturer. Each of these recognitions has enabled us to continue manufacturing American-made bolts, screws, and studs for a variety of military customers, including:

  • U.S. Government
  • Military OEMs
  • Military distributors
  • Foreign OEMs and distributors

As experts in per-spec, limited-run, specialty fasteners, we’re proud to support both non-military and military products and applications with some of the strongest, long-lasting fasteners on the market.

Unique products require unique fastener solutions, and we’re here to help you find them. Trust Wilson-Garner’s high-quality, limited-run, American-made bolts, screws, and studs for your MS fastener needs. For more information, reach out to our team online.

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