19pcs/Set Bimetal Metal Hole Opener Drill Bit Shank

16PC set parameters:
A2 A4 post each, 300mm extension rod 1piece 19mm 20mm 22mm 25mm 29mm 32mm 35mm 38mm 44mm 51mm 57mm 67mm 76mm hole opener each Packing: Aluminum box Size: 32*23.5*5.5cm Weight: 4kg Product Name: Bimetal hole opener, using M42 as material, the product is made of precision electron beam welding, and then subjected to vacuum high temperature quenching, its biggest advantages: aluminum, steel, cast, wood, plastic, plaster Plate, stainless steel and other drilling operations. 1. When using the hole opener, please be sure to master, select, control, and tachometer and add coolant continuously to prevent the blade from cracking. For example, use high-speed gun drill, and control the switch during operation. Open and close as much as possible to reduce its speed, widely used in the drilling of various types of drills on bench drills. 2, the hole iron plate is more than 5mm, first open about 1mm deep, and then use the positioning drill to drill through the hole through the hole, which is more convenient to discharge iron filings.