3Pcs Step Drill Bit Set (4-12/4-20/4-32)

Buying the three as a set rather than singly makes sense for anyone doing this work regularly, for a reason that is about wear rather than coverage. The small and middle bits do most of the work and blunt first, while the large one is used occasionally. Owning all three means you use the smallest bit that reaches your size, which is faster, generates less heat and spreads the wear, instead of using one large bit for everything and blunting its lower steps on holes a smaller bit should have made.

The case matters more than it sounds too. A step drill is a cone of exposed cutting edges with nothing protecting them, and loose in a toolbox those edges chip against other tools. A chipped step cuts an out of round hole and cannot easily be repaired.

Something we should mention rather than paper over. The step increments given for this set do not match the ones printed on the individual bits. The set states 1mm steps for the 4 to 12 and 2mm steps for the 4 to 20 and the 4 to 32, while the individual listings give 1mm for all three. The set's figures are the credible ones: a 4 to 32mm bit in 1mm steps would need twenty nine separate steps, which is not how these are made. Rather than assert a figure we cannot stand behind, we will read the actual steps off the stock and tell you before you buy.

HSS, heat treated, titanium coated, and as with all step drills these are for sheet material rather than thick sections.

Buyers are electricians and panel builders, air conditioning and ducting installers, sheet metal fabricators, signage and display makers and hardware shops.

Message 94 77 111 8880 and we will confirm the exact sizes. Delivered island-wide.