... nuts, square nuts, etc.), flat washers, spring washers, mudguard washers and so on. Our main material is iron steel, stainless steel, brass ... .Knurling drop-in anchor3 .Half knurling drop-in anchor.4.stainless steel non-knurling drop-in-anchor5. brass drop-in anhor6 ... types have many sizes .About the material we have iron,stainless steeel and brass.If you are interest in our drop-in ...