Stainless Steel Hex Cap Screws, Hex Flange Bolts, and Hex Tap Bolts
Though these products go by many names, including hex bolts, flange bolts and hex screws, the characteristic that they all share is a hexagonal head, designed to be driven by a wrench. They all are commonly referred to as both bolts and screws. Hex Cap Screws are unique because of the threading. Hex Cap Screws are partially threaded with a shoulder beneath the head. Tap Bolts are fully threaded up to the hexagonal head. The unique characteristic of Flange Bolts is the design of the head, from which they get their name. The "flange" of the bolt is a built in (integral) washer. In Imperial sizes, this washer is serrated to act as a lock washer.
18-8 Stainless Steel
A hex cap screw is a cap screw with a hexagonal head, designed to be driven by a wrench (spanner). An ASME B18.2.1 compliant cap screw has somewhat tighter tolerances than a hex bolt for the head height and the shank length. The nature of the tolerance difference allows an ASME B18.2.1 hex cap screw to always fit where a hex bolt is installed but a hex bolt could be slightly too large to be used where a hex cap screw is designed in.
316 Stainless Steel
316 stainless steel provides the strongest corrosion resistance and is non magnetic. Hex cap screws and tap bolts in 316 Stainless Steel are used for salt water and water treatment applications, food processing prep area equipment. Used on boats, docks, oil gas refining plants for direct use in salt water. Compliance with ASTM and certification available upon request.
A2 Stainless Steel
Comparable to 18-8 Stainless Steel, A2 Stainless Steel is the standard for Metric sized fasteners. Metric hex cap screws are corrosion-resistant. A hex cap screw is a cap screw with a hexagonal head, designed to be driven by a wrench. A DIN 930-933/ISO 4014-4017 compliant cap screw has somewhat tighter tolerances than a hex bolt for the head.