Zinc-Plated Grade 30 (G30) Proof Coil Chain in a heavy-duty carry bag. KingChain Grade 30 chain is an excellent general purpose, low carbon utility chain. The chain is manufactured to NACM standards. Each link is proof tested two times and the break load is 4 times the Safe Work Load (design factor 4:1). It is recommended for applications that do not require high strength-to-weight ratios. It is often used on farms, in industry and at home for general purpose applications, such as pulling stumps, lashing cargo, truck tailgates and guard rails. Chain is zinc plated for a bright, attractive finish with moderate corrosion resistance. Do not use for overhead lifting. Never exceed the Safe Working Load (SWL).