#4-40 Black Oxide Stainless Steel Button Head Socket Cap Screws

#4-40 Button Head Socket Cap Screws are bolts or machine screws with a Hex or Allen drive style.

• Commonly referred to as allen bolts, button heads, or socket head screws
• Clean and unstamped domed head with a flat bottom that protrudes above the installation surface
• Cylindrical head and hexagonal drive style
• Head diameter is nominally 1.5 times or more that of the screw shank (major) diameter
• Chemically treated to add a mild extra layer of corrosion and abrasion resistance
• Sleek black finished look

Black Oxide Stainless Steel Fasteners are commonly used in industries where the durability of Stainless Steel is required, but a smooth black look is desired. These industries include firearms, automotive (car and motorcycle), camping gear, archery, knife builds and product manufacturing.