Track Roller System of Measurement Metric Shaft Diameter 10 mm Shaft Material Alloy Steel Shaft Material Grade 52100 Shaft Type Concentric Drive Type Hex Socket Drive Location Stud Shaft Thread Size M10 x 1.0 Shaft Thread Length 15 mm Head Diameter 18 mm Head Length 10 mm Hex Drive Size 4 mm Overall Length 55 mm Standards AS 9100 ISO 9001