Ingco HSS Drill Bit 4.00mm, 10-Piece Set (DBT1100403)

Our review

This is a ten-piece pack of 4.0mm high-speed steel drill bits from Ingco, supplied in a poly bag. Each bit measures 75mm overall with 43mm of usable flute, so you get a reasonable shank to hold in a chuck while still reaching through thinner material. Because they are HSS, they suit general drilling in metal, wood and plastic rather than masonry, which needs a carbide tip. The 4.0mm size is a common choice for pilot holes before driving screws, for small bolts and for light fabrication work. Buying ten of one size makes sense if you break bits often or keep a workshop stocked. Before ordering, confirm your drill chuck accepts the shank and that 4.0mm matches the hole you need; if you want a range of sizes, a mixed set may serve you better. Compare bit material, point angle and coating, since those affect heat resistance and how long the edge lasts. Available on Sokonia.