PE7113 – 15pc Bi-Metal Hole Saw Kit For cutting holes in wood drywall steel plate conduits & plumbing pipes. High Speed Steel Bi-Metal cuts smoother and faster perfect for plumbing electrical maintenance and general construction. M3 HSS Cutting Edge Includes 11 Bi-Metal Hole Saws Saw Sizes: 19mm 22mm 25mm 32mm 35mm 38mm 44mm 51mm 57mm 64mm 76mm. Cutting Depth: 38mm Arbors: 1 x Fits 14mm-30mm 1 x Fits 32mm-152mm Extension Bar: 12in/300mm 1 x Ejector Spring 1 x Adaptor Tips for Hole Saw Use… Lubricant: Holesaws cut non-ferrous metals more efficiently with the use of lubricant. Cast iron should be cut dry. Aluminium cutting for best results use beeswax or paraffin. Feeds: Even pressure will produce the most efficient cutting action. Excessive pressure will dull teeth and shorten life of holesaw.