A2 Stainless Steel 304 Hex Socket Bolt

An A2 Stainless Steel 304 Hex Socket Bolt (also known as a socket head cap screw or Allen bolt) is a type of fastener made from A2-grade stainless steel (304), featuring a hexagonal socket drive (internal Allen key drive) and a cylindrical head with a chamfered top.

Key Features:

Material: A2 (304) Stainless Steel – Offers good corrosion resistance, durability, and moderate strength. Suitable for indoor and mildly corrosive environments.

Head Type: Socket Head (Cap Screw) – Cylindrical with a flat bearing surface and internal hex drive.

Drive Type: Hex Socket (Allen Key) – Requires a hex key (Allen wrench) for installation.

Thread Type: Typically metric (M) or imperial (UNC/UNF) depending on the standard.

Finish: Usually natural mill finish (self-color), but can be polished or electropolished for enhanced corrosion resistance.

Strength Class: Comparable to ISO 3506 Class 70 (tensile strength ~700 MPa).

Common Applications:

Machinery & equipment assembly

Automotive & aerospace components

Marine & food processing industries (due to corrosion resistance)

Precision engineering where a flush or low-profile fastener is needed

Standards & Specifications:

DIN 912 / ISO 4762 (Metric hex socket head cap screws)

ASME B18.3 (Imperial sizes)

ASTM F837 (Stainless steel socket head cap screws)

Alternatives & Variations:

A4 (316) Stainless Steel – Higher corrosion resistance for harsh environments (marine, chemical).

Black-Oxide or Coated – For added protection or aesthetic purposes.

Low-Head or Button Head – For reduced protrusion.