... High density and mechanical strength Special treatment can be made on request High strength of thread Fiberglass winding tube for ... and mechanical strength6. Special treatment can be made on inner and outer surfaces on request.7. High strength of threads 1. ... Insulators, Bushing, Surge Arrester, High-voltage Current Limiting Fuse, On-load tap changer,Power reactor and HV testing device, Breaker, etc ...