144 x 10mm Stainless Steel Studs w/ 2mm Loop. 10mm Pad w/ 2mm LOOP Stainless Steel Studs - Clutch Options. 10mm Flat Pad with 2mm loop. However, all stainless steel contains tiny traces of nickel. Laboratory testing of a sample of the stainless steel used has shown that the product is well within a PASS for piercing components containing a micro amount of nickel and well within the standard required for piercing components.