Koopi Bi-Metal Hole Saw with Arbor, 1-3/4-inch ? Feature - Alternating teeth size enhances hole saw performance - cuts faster and lasts longer.- Sharper Tooth Geometry cuts material faster for faster drilling.- Increased wall thickness improves durability and minimizes tooth loss.- Thick, hardened backing plates prevent thread stripping.- Increased high speed steel height (M42 HSS) improves hole saw durability.- Come with a heavy duty arbor, fits hole saws 1-1/4 inch - 6-5/8 inch.? Specification- Cutting Diameter: 1 3/4 inches / 38 mm- Cutting Depth: 1-1/2 inches / 38 mm- Arbor size: Shank size: 7/16 inch; Thread size: 5/8 inch-18.- Materials: M42 HSS BiMetal- Color: Red? Package Included- 1 x 1.75in hole saw- 1 x hole saw arbor with pin- 1 x pilot bit- 1 x hex key?Warm Tips - For longer saw life and lower operating cost- When mounting arbor, lift up the disc with the pins and then screw the arbor down into the hole saw as far as it will go.Fit the drive pins into the pin holes in the hole saw by turning the hole save backwards.Push the pins in.Check that they are securely locked.- Check that the arbor shank is securely inserted in the chuck on the drive unit.Tighten with chuck key.- Cutting oil should be used when sawing steel.Do not use cutting oil when sawing cast iron.The cutting pressure should, however, be high so that each tooth cuts deep.Paraffin can be used when sawing aluminum.- Use the correct rotation speed!Too high or too low a speed will decrease the life of the cutting edge.- If the hole saw vibrates during sawing, the teeth may become damaged and break.The result is often a rough, imperfect hole.- Clear away chips and plugs frequently in order to prevent overheating.