13pcs Hole Saw Set, can be used with electric drill and gadget machine, size in: 16mm/0.63", 18mm/0.71", 20mm/0.79", 22mm/0.87", 25mm/0.98", 26mm/1.02", 28mm/1.10", 30mm/1.81", 35mm/1.38", 40mm/1.57", 45mm/1.77", 50mm/1.97", 53mm/2.09" Sharp and anti-cut gears with lower consumption give the product a long service life. Made of high speed steel, sharp blade, smooth and fast cutting. Suitable for steel plate, iron plate, stainless steel and all kinds of thick materials. The depth Maximum perforation depth is 5 mm. Cutting fluid or drilling lubricant is recommended (the type of fluid depends on the material being machined). Carbide teeth for fast cutting of clean, round holes. Suitable for handheld electric drills, stand motor drills, and mobile magnetic band drills. Cuts fast, accurate holes in stainless steel, mild steel, iron, copper, and brass. Can drill about 20 mm deep in wood and about 5 mm deep in stainless steel.