Surface Roughness : Ra 0.2 Torque Capacity : M4X12X20 mm Structure : Deep Groove Model Number : CF4/KR12 Coatings : No Material : Stainless Steel Model : CF4/KR12 Accuracy level : ABEC-7 Screw Outer Diameter : M4 Outer Diameter : 12 mm Length : 20 mm Weight : 8.9 g Bearing material : Stainless Steel AISI304 Welcome to Lingfeng Store