Track Roller System of Measurement Inch Shaft Diameter 5/8 in Shaft Material Alloy Steel Shaft Material Grade 52100 Shaft Type Concentric Drive Type Hex Socket Drive Location Stud Shaft Thread Size 5/8 In.-18 Shaft Thread Length 7/8 in Head Diameter 1 1/8 in Head Length 1/2 in Hex Drive Size 5/16 in Overall Length 3 in Standards AS 9100 ISO 9001