API standard NOV materical OD of sheave mm(in) :1270mm(50in ) good quality use more than 5years welcome to tiger family a customer ask how do u make rotary table, travelling block ,hook, crown block mast ?can u show your workshop to us ? ok , i will show the workshop and processing to end user to know about , wish you can see what you get . they are as same as HH ,chinese NOV, not different! let ...