Trend 50/19 x 8mm HSSE Steel Helical Plunge Bit 5mmTooling for use on webbed aluminium and UPVC extrusions by window and door fabricators. Cutters are produced in special high speed steel (HSSE) to ensure a clean cut and resist the abrasive nature of anodised aluminium extrusions. Cutters are designed to plunge and machine or mill lateral slots All tooling for aluminium should be used with a coolant, wax stick, or lubricant. The material being worked on should always be securely clamped in a machine