... 20 years experience in special fastener Name: hex nut with internal thread and castle screw Ability for the material ... D,Gr.36,Gr.58,1010,1015,1016,1020,1045,etcAlloy steel4130,4140,G51150,etcStainless steel201,202,301,302 ... our own way to supply youthe high quality products with lowest price and delivery on time as we can ... that you could avoid lots ofrisks. hex nut with internal thread and castle screw