All Military Specification callouts have different meanings worth noting when buying Wire Rope, Cable, and Strand. Knowing the difference between the various callouts ensures you choose the right product for your applications. While some companies have limited types of Mil-Spec products, Strand Core has a wide range available. Strand Core sells five different Mil-Spec products: Mil-DTL-83420, MIL-DTL-87161, MIL-DTL-18375, MIL-DTL-83140, and Mil-W-18242B. All five specifications are approved for use by all Departments and Agencies of the Department of Defense. Continue reading to learn more about each of these Military Specifications.
MIL-DTL-83420 (QPL-83420):
This specification explains the requirements for flexible wire rope designed for aircraft control. MIL-DTL-83420 covers requirements of carbon steel and corrosion-resistant steel for the flexible wire rope.
There are two types of wire rope that MIL-DTL-83420 includes: Type I (Non-jacketed Wire Rope) and Type II (Jacketed Wire Rope). Type I can operate within a -65 Degree F to +250 Degree F temperature range in dust, fuel, wind, and oil spills, in wash-down, and other environmental stresses and aircraft experiences. Type II can perform to the same operations, but with a jacket attached to the wire rope.
In terms of compositions, there are specific guidelines for all materials that can be read about on pages 4 & 5 of our Mil-DTL-83420 guide here. The key takeaway is that there are two different Compositions for MIL-DTL-83420: Composition A (made with Carbon steel, zinc, or tin over zinc-coated) and Composition B (corrosion-resistant steel).
MIL-DTL-87161 (QPL-87161):
This specification explains the requirements of non-flexible wire rope used in aircraft applications. MIL-DTL-87161 covers the requirements for carbon steel and corrosion-resistant steel for wire strand used in aircraft applications.
The two types of wire strand within this specification are Type I (non-flexible, 1x7 class) and Type II (non-flexible, 1x19 class). Both types have two Constructions, one for Right Lay and the second for Left Lay. Both types must perform to specified levels for breaking strength, stretch limits, ductility of steel, test load, and coating adherences. There are two composition types of the wire rope. Composition A is made of carbon steel that is zinc coated. Composition B is made of corrosion-resistant steel. More information of Type I and Type II MIL-DTL-87161 can be found on pages 4 & 5 of our guide here.
MIL-DTL-18375 (QPL-18375):
This specification covers the requirements for corrosion-resistant, nonmagnetic steel wire rope used in aircraft flight controls. The wire rope can operate within a -65 Degree F to +250 Degree F temperature range in dust, fuel, wind, and oil spills, in wash-down, and other environmental stresses and aircraft experiences.
For material, corrosion-resistant steel that is in accordance with SAE HS-1086 must be used. Each wire of the wire rope must be coated with a friction-preventing, non-corrosive lubricant. All MIL-DTL-18375 wire rope must meet the breaking strength, endurance, stretch limits, ductility of steel, test load, magnetic permeability and operating temperature range that has been provided. More information can be found on page 4 of our MIL-DTL-18375 wire rope guide.
MIL-DTL-83140 (QPL-83140):
This specification covers the requirements for rotation-resistant preformed stainless steel wire rope intended for aircraft rescue hoists, utility, retrieval hoists, and winching applications.
The preformed stainless steel wire rope is available in two types. Type I is a rotation-resistant 19x7 construction that is used for hoisting (vertical) operations. Type II is a rotation-resistant 10x7 construction (7x19 IWRC) used for winching (vertical, horizontal, or at-angle) operations. Similar to other Mil-Spec products, packaging, testing and certain performance levels must be met.
Mil-W-18242B covers the requirements for corrosion resisting steel wire rope used for minesweeping.
The critical takeaway to understand about Mil-Spec products is they are designed with specific applications in mind and have strict rules for materials, sizes, performance, and packaging. Due to the guidelines for each of the Mil-Spec products being particular, buying Mil-Spec guarantees strength, durability, and a high-quality product that has been manufactured to the optimal level.
If you are interested in learning more about the Mil-Spec products sold at Strand Core, please visit our website here. If you want to learn more about the various specifications that our Strand, Wire Rope, and Cable products are manufactured to, check out our Specifications webpage. If you have any questions, our team is happy to help! Reach out to us by email through sales@strandcore.com or by phone at 800-983-9926.