4-40 Socket Head Cap Screws

4-40 Socket Head Cap Screws | The Nutty Company, Inc.

4-40 Socket Head Cap Screws

#4-40 socket head cap screws in USS coarse (UNC) thread, made from heat treated alloy steel with a black oxide finish. We stock 1/8", 3/16", 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 7/8", 1-1/4", 1-1/2" lengths. They take a 3/32" hex key. Shorter lengths are fully threaded (FT) and longer lengths partially threaded (PT).

Specifications

Size: #4-40 (USS coarse)
Lengths: 1/8", 3/16", 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 7/8", 1-1/4", 1-1/2"
Hex key: 3/32"
Tap drill: #43
Material: alloy steel, ASTM A574
Finish: black oxide
Strength: 180,000 psi minimum tensile strength (ASTM A574)

Common Uses

Machinery and tooling
Jigs and fixtures
Counterbored holes

FAQ

What hex key fits a #4-40 socket head cap screw?
A 3/32" hex key (Allen wrench).

What tap drill do I use for #4-40?
Use a #43 drill for a standard 75% thread.

Will black oxide socket screws rust?
Black oxide is a thin conversion finish with a light oil. It gives mild rust protection indoors and a clean dark look, but it is not made for outdoor or wet use. For outdoor, wet or washdown areas, use our stainless steel socket screws.

Free shipping on orders over $100, and orders placed before noon EST ship the same day. Purchase orders are accepted from government agencies, schools, hospitals, municipalities and companies with established credit with The Nutty Company, Inc.