supply of manufacturer supply of single coil spring washer conforming to rdso drawing. no. t-10773manufacturer supply of single coil spring washer conforming to rdso drawing. no. t-10773,manufacture and supply of single coil spring steel washer confirming to rdso drg. no. t-10 773 to suit 25mm dia bolt/plate screw. (this is a safety item). specification: irs specification no. t-42-2020 (first revision). [ warranty period: 30 months after the date of delivery ] ] , manufacture and supply of single coil spring steel washer confirming to rdso drg. no. t-10 773 to suit 25mm dia bolt/plate screw. (this is a safety item). specification: irs specification no. t-42-2020 (first revision). [ warranty period: 30 months after the date of delivery ] ]