Track Roller System of Measurement Inch Shaft Diameter 2 1/4 in Shaft Material Alloy Steel Shaft Material Grade 52100 Shaft Type Concentric Drive Type Hex Socket Drive Location Stud Shaft Thread Size 2 1/4 In.-12 Shaft Thread Length 2 1/4 in Head Diameter 3 1/2 in Head Length 1 1/4 in Hex Drive Size 5/8 in Overall Length 7 3/4 in Standards AS 9100 ISO 9001