Military Screws — Machine, Socket Head & Set Screws

Military screws span the full range from precision machine screws in avionics enclosures to high-torque socket head cap screws in structural joints and setscrews locating rotating machinery — every configuration governed by its own dedicated federal or military specification.

Configurations: Machine, Socket Head, Set Drives: Slotted, Cross-Recessed, Hex, Spline Governing Specs: 7 Federal Specifications

Screw Configurations We Manufacture

Head style and drive geometry determine torque capability, clearance requirements, and installation method.

Machine Screws

Slotted, cross-recessed, or hex head, lighter-duty fasteners typically paired with a nut for electronics, panel, and general assembly work.

Socket Head Cap Screws

Internal hex or spline drive recess allows high installation torque in confined or recessed spaces where an external wrench can't reach.

Set Screws

Headless fasteners driven fully into a tapped hole to locate shafts, collars, or gears without a protruding head interfering with rotating assemblies.

Overview

Because "screw" covers such a wide range of fastener geometries, the federal specification family splits the category by head and drive style: FF-S-85 covers slotted and hex head cap screws, FF-S-86 covers socket-head cap screws (one of the most actively revised specs in the entire family, with a new revision as recently as 2025), and FF-S-92 covers slotted, cross-recessed, or hex head machine screws.

Setscrews get their own dedicated pair of specifications — FF-S-200 for hexagon and spline socket-drive headless setscrews, and FF-S-210 for square head and slotted headless configurations. Point style matters as much as head style: cup points (recommended wherever practical) bite into the mating shaft for strong holding power, while flat or half-dog points avoid marring hardened or finished surfaces.

Self-tapping and wood screws are covered separately under FF-S-107 and FF-S-111 respectively — both now inactive for new design but retained for legacy replacement work.
Material and finish selection follows the same logic as bolts: alloy steel for general strength, CRES for corrosion resistance, and nickel superalloys for high-temperature service.

Which Screw Family Do You Need?

Application

General Assembly: FF-S-85 (slotted/hex cap screws) or FF-S-92 (machine screws) cover general-purpose assembly, depending on whether the screw drives into a tapped hole directly (FF-S-85) or pairs with a separate nut (FF-S-92).

Applicable Standards

Explore the individual military screw specifications Ananka manufactures to.

FF-S-85Slotted/Hex Cap Screw FF-S-86Socket-Head Cap Screw FF-S-92Machine Screw FF-S-200Socket Setscrew FF-S-210Square Head Setscrew FF-S-107Tapping & Drive Screw FF-S-111Wood Screw MIL-DTL-18240Self-Locking Element

Military Screws — Frequently Asked Questions

What's the difference between a cap screw and a machine screw?

A cap screw is designed to be driven directly into a tapped hole with a larger, more precisely controlled head bearing surface for higher clamp loads. A machine screw is typically lighter-duty and often paired with a separate nut.

Which point style should a setscrew use?

Cup point is recommended wherever practical for the strongest holding power. Flat or half-dog points are used on hardened shafts or where marring the mating surface is a concern.

Can screws have a self-locking feature?

Yes — MIL-DTL-18240 covers self-locking thread elements (strip or patch configurations) applied directly to a bolt or screw's threads as an alternative to lock-wiring, for service up to 250°F.

Need Military Screws to Print?

Ananka Fasteners manufactures military screws to federal and military specifications with full material traceability and Mill Test Certification on every lot.

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