supply of different items of core approved vendorsdifferent items of core approved vendors,annealed copper split pin 4mm x 36mm as per is : 549-1974 & is : 191-2007 (part-vii ) (frtp-2) & rdso specification no.ti/spc/ohe/fasteners/0120, make:core approved vendors accep ted only [ warranty period: 30 months after the date of delivery ] ] , copper split pin 2.5 x 25 mm for catenary wire dropper clip bolt as per is: 5 49:2005 and as per rdso: spec.no.ti/spc/ohe/fasteners/0120 rev-1 make: core approved vend ors accepted only [ warranty period: 30 months after the date of delivery ] ] , supply of copper rivets of size 6x60 mm as per rdso specification no.ti/spc/ohe / fa steners /0120 rev-1 (march-2017 or latest), make - core approvd vendors accepted only [ warran ty period: 30 months after the date of delivery ] ]