HTV hollow core insulators mold 1.OEM 2.passed ISO 9001-2000 2. ... this field we have so many experience in making HTV hollow core insulatos from 110kv to 1000kv 1.Mold cavity: design according ... material: P20, S50, S1363.Mold case material: S50,etc4.Mold core material: P20, etc5.Value-added service: polishing, nitrogen treatment, black ...