TYPES: PLAIN WASHER , PLAIN BIG & SMALL OD WASHER , SPRING LOCK WASHER , SPRING WASHER HEAVY DUTY , TOOTH WASHER , STAR WASHER , TAB WASHER WITH ONE & TWO TAB These are designed as per drawing and customers specifications: Size range: M12 to M150 & 1/2" to 6" Specifications: IS (GR.8.8, 10.9, 12.9,) BS (GR. R,S,T), ASTM A193 (GR.B7), ASTM A320