These can drill many holes in flanges and webs of rolled steel sections simultaneously. It is also possible to punch holes, and this is particularly useful where square holes are specified such as anchor plates for foundation bolts. While this method is fasterpared to drilling, punching creates distortion and material strain hardeningSep 11, 2017 · A simple way of producing large diameter holes in metal plate is to mark out the required hole size and drill a series of small, interconnecting holes (5 or 6mm dia), saw them where there is no interconnection and then file the peaks until you reach the marked out diameter. Particularly easy using a pillar drill.Product Description Product name solid carbide Internal cooling drill bit Place of Origin China Brand name KTL Tools Model KTL-C2-KTL00 Coating TiAlN/AlCrN HRC 60 Suitable for Cast iron, carbon steel, alloy steel, non-ferrous metals, etc. Material Cemented carbide Flutes 2 flutes Size D22.5*12...ISCAR is introducing the CHAM IQDRILL drill family for the drilling range of 33 to 40 mm with 1.5, 3, 5 and 8 length to diameter ratios. The CHAM IQDRILL features a unique design, utilizing the carbide flexibility for self-locking eliminating the need for clamping accessories. The robust structure of the drill with the concave cutting edge design enables drilling at high feed rate, providing very accurate IT8 – IT9 hole tolerance.