Product Features 1 . Harden material Shoulder screws are made of carton steel . 2 . Eco-frendly Stainles steel shoulder screw meets RoHS or REACH requests . 3 . Good quality 4 . Not easy to be rusted 5 . No burrs or scratch . 6 . High tesile strength 7 . Steady performance . Tips for application 1 . Driven by slotted screwdriver . 2 . Insert shoulder screws into hole before driving . 3 . Do not over standard torque .