Item Specifications UPC 842176136639 Package Quantity 50 Size 5/16"-18 x 3/8" Head Style Flat Counter Sink Angle 82 Degree Head Diameter 0.656" Head Height 0.198" Drive Style Allen Hex Key Drive Size 3/16" Inch / Metric Inch Thread Size 5/16"-18 Thread Dia. 0.3125" Thread Class Class 3A Coarse / Fine Coarse Threads Per Inch (TPI) 18 Thread Coverage Full Thread Length 3/8" Thread Length Dec. 0.177" Material Alloy Steel Grade Grade 8 Finish Black Oxide Specification 1 ASME : B18.3 Tensile Strength 120,000 PSI Core Hardness Rockwell C32 Item Type Socket Screws Product Code 5150-10430 SKU 721164