roofing bolts with nut 2)Size: M6~M20,1/4"~3/4"... 3)Length: 12~200 mm;1/2"~12" 4)Surface treatment: plain, black, zp,HD Item: roofing bolts with nut Material:carbon steel, stainless steellength:8-300thread size:M4-M20Surface: zinc plated, nickle plated, chorme plated, polishing, magni, paintingPacking:bulk packingDelivery :25 days