... of fiberglass or ECR-fiberglass (FRP/GRP) epoxy resin 2.high mechanical strength FRP Threaded Rod is made of fiberglass ... or ECR-fiberglass (FRP/GRP) and epoxy resin, With high mechanical strength ... temperature resistance, age resistance, used for silicone rubber composite insulator, pocelain insulator, composite hollow insulator, Pillar insulator, cross arm insulator, ...