Roller chain is designed as per API Spec 7F standard, which meets and exceeds ISO606-94, ANSI.B29. 1M-93, BS228-94, JISB1801 standard. Under continuous         test and strict product quality inspection, roller chains are assured of anti-fatigue,   anti-friction, anti-abrasion, anti-tension load and impact load as well as the precision mesh of same chains gears. Our roller chains are widely used in petroleum drilling machines and pumping units in the oilfield of China.