... tire studs 2. flat tyre studs 3.size:9-10,9-11,9-12,9-13,9-14all the specifications can be used in cars ... . Length(H)10 +/-0.15 mm,11mm,12mm,13mm ... ,14mmHead Diameter(D)9+/-0.2 mmShaft Diameter ( ... tire studs, tyre nails :Chemical composition: WC-80%+Co-10% Density: (g/cm3):13.0-13.5Hardbess HRA :>90 ...