High speed steel holesaw set specifically for Electricians. It features the sizes they use every day and come in a sturdy plastic carry case. HSS Bi-Metal With 8% cobalt alloy for extreme resilience and long lifetime. Designed to cut quickly and steadily through a wide variety of materials including Acrylic, metal, aluminium, plastic, plasterboard, PVC and wood. Progressive tooth strip for high cutting performace and fast chip clearance HSS bi-metal with 8% cobalt alloy for extreme resilience and long lifetime.