Thread - UNC (Imperial coarse thread). Material - Grade 5 (8.8) High Tensile Steel. Finish - Bright Zinc Plated (bzp). TECHNICAL INFORMATION. Size - 1/2"-13. 1/2" 3" 3/4" 5/16" 13. 1/2" 2 1/2" 3/4" 5/16" 13.
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