tender for standard duplex roller chain (1/2x5/16 size). pitch-12.7mm, roller dia- 8.51mm along withrelevant data. breaking load 3180 kgf.(min.) av. wt. 1.36kg per meter. make- renond-xd, diamond,tripcon engineering. [material specn.- bs 228 or din 8187, rolon chain no - 08b-2 / dr 1278] .