Taper shanks style of japan BT30,BT40,BT50,BT60 good quality low price JIS standard Japan MAS 403 BT equals to JIS B 6339-1998Type of shankDD1dLL1L2L3L4bBT3031.7546M1248.42013.616.3216.1BT4044.4563M1665.42516.622.6216.1BT5069.85100M24101.83523.235.4325.7BT60107.95155M30161.84528.260.1325.7