... steel welded link chains, transport chains, short/long link chain, proof coil chain, snow chains, chain block, lever block and electric hoist for more than ... , United State etc. 1) Grade: G80, G70, G60, G43, G30 alloy welded round link chain2) Surface treatment: Self color, black ... Sampling and breaking test 11.Calibration 12. Heat treatment 13. Proof load test 14. Black oxide, zinc plated and hot dip ...