Thumb Screw Knurled With Shoulder Head 18-8 Stainless Steel Thread Size 8-32 Length 5/16 In Head Diameter 0.438 In Head Height 0.219 In Shoulder Dia 0.375 In Screw Shoulder Length 0.094 In Class 2A Rockwell Hardness B85-B95 Tensile Strength 80 000 PSI Finish Plain