Cutting Behaviour Using Variable Feed and Variable Speed when Drilling Stainless Steel with TiN-Coated Carbide Drills

(x) = fc[1+a sin(2π(x/L) + 3/2π)], ω(x) = ωc[1+b sin(π(x/L) + 3/2π)], respectively. The results indicate that variable feed machining is superior to constant feed machining with respect to tool life, burr height, and surface roughness. The amplitude of variation of feed, a = 0.8 and the amplitude of variation of speed, b = 0.07, is optimum for maximum tool life. The range of surface roughness from the variable feed and variable speed can be limited from 0.7 μm to 3 μm. The cutting-edge wear and outer corner wear were the dominant mechanisms of the drill wear.