- Hex Head Cap Screws feature hexagon-shaped heads for socket or wrench tightening. -18-8 Stainless Steel construction is easy to sanitize and resists corrosion from water, humidity, and oxidizing acids. Dimensional Standards / ASME B18.2.1 Drive / Hex Fastener Length / 1 1/2 in, 1 1/2 in Finish / Plain Material / Stainless Steel, Stainless Steel Material Grade/Class / 18-8 Material Quality Standard / ASTM F593 Head Style / Hex Head Height / 5/32 in Head Width / 7/16 in Globally Sourced / Globally Sourced Minimum Thread Length / 3/4 in Threadlocker Minimum Temperature / 1/4"-20 Thread Pitch / Partially Threaded Thread Size / Coarse, 1/4"-20 Thread Direction / Right Hand Thread Fit / 2A Pack Size / Small Pack System of Measurement / Inch Tensile Strength / 85,000 psi Overall Length / 1 1/2 in Screw Size / 1/4 in Rockwell Hardness / HRB95