oblique hole chamfering device inverted taper hole screw sinking knife chamfering knife 90 degree drill bit deburring trimming and reaming Material:HSSHigh Speed Steel4241, Titanium Coated Application:Ideal for cutting through metal,wood,plastic and thin iron plate (hardness <25 degrees) Chamfer range:2-5mm, 5-10mm, 10-15mm, 15-20mm, Shank diameter: 6mm, 8mm, 10mm, 12mm, Head diameter: 10mm, 14mm, 21mm, 28mm 90 Degree angle on the point for sharp and precise countersinking, used for workpiece circular aperture chamfering or cone hole This bits should use the bench drill , it is easy to shake and it will affect the chamfering effect if you use the hand drill. Product Details This 90 Titanium Coated chamfer tool is convenient for chips to get out and prevent metal chips from splashing and round shanks. Size(hole chamfer size x length) 2-5mm(2-5 mm x 45 mm)5-10mm(5-10 mm x 47 mm) 10-15mm(10-15 mm x 62 mm)15-20mm(15mm-20 mm x 82 mm) Wide Range of Applications Suitable for hardness under 25 artifacts,like the thin board, such as wood, PVC board, aluminium sheet, insulating plate or thin plastic sheet, etc. First Step:Pilot Hole First drill the hole in wood or plastic to locate or guide a screw and expand the size according to the tap. Without a pilot hole, the screw may get too tight and either broke the material or snap the screw completely. Second Step:Install the chamfer tool Install the chamfer drill on the bench drill. If you need to chamfer 16mm hole, you can choose 15-20mm chamfering device. Add water or cutting oil to cool when chamfering. Third Step:Clearance Hole Finally screw on until flush with the horizontal. This bits should use the bench drill , it is easy to shake and it will affect the chamfering effect if you use the hand drill. colorgoldsilver. weight185g*1. pack*4pcs.