Track Roller System of Measurement Inch Shaft Diameter 2 3/4 in Shaft Material Alloy Steel Shaft Material Grade 52100 Shaft Type Concentric Drive Type Hex Socket Drive Location Stud Shaft Thread Size 2 3/4 In.-12 Shaft Thread Length 2 5/8 in Head Diameter 4 1/4 in Head Length 1 3/8 in Hex Drive Size 5/8 in Overall Length 9 in Standards AS 9100 ISO 9001