Track Roller System of Measurement Inch Shaft Diameter 1/2 in Shaft Material Alloy Steel Shaft Material Grade 52100 Shaft Type Concentric Drive Type Hex Socket Drive Location Stud Shaft Thread Size 1/2 In.-20 Shaft Thread Length 3/4 in Head Diameter 7/8 in Head Length 7/16 in Hex Drive Size 1/4 in Overall Length 2 3/8 in Standards AS 9100 ISO 9001