Review on 🔩 Irwin Speedbor Drilling 10 Piece Set 1801022: The Ultimate Solution for Effortless and Precise Drilling! by Marcel Robinson

This set is not primarily used for building, but as an alternative to Forstner bits, sizes from 1/2" to 1 3/8". I tried using it on lumber like 2x4. The drill goes through the 2" side in literally seconds, leaving a relatively clean hole and not much debris on the exit side. To test this for dividing the workpiece, I intentionally used a 7/16" drill bit in thin chipboard. Mine broke the piece right away. I then attempted to pre-drill a pilot hole the size of a screw tip before using the Speedbor Max bit. In this case the drill drilled a very good hole without tending to split the piece. The hole was very clean with sharp edges and didn't require much force to push the drill into the board. However, there are at least a few issues: 1. A Several reviews have shown that the bit's shank has warped during use. This is definitely a big problem for me as I can't use the drill for fine work unless it moves vertically. Please note that all the bars appear to be heat treated, but I don't have a hardness tester so I can't tell if the heat treatment has resulted in a significant improvement in the bit's hardness and stiffness. The largest bit in the set is the 1 3/8" which has a significantly larger stem and quick change tip. Given the many complaints I'm not sure why this was done for just a bit. I find that all bits from 1 would benefit from a larger shank to eliminate any possibility of bit twisting. 2. Bit sharpening is very rough. I have actually used needle files to trim the ends of the spurs. As a former quality controller in a metalworking industry, I don't understand why why a factory cannot use proper equipment to grind clean and sharp cutting edges.This is a mass produced product.The added cost of such grinders will be negligible in the tooling cost.