Description of π§ Bosch AutoStart Carbide Mandrel with HDGQA for Enhanced Performance
AutoStart pilot bit is spring-loaded. Retractable shaft allows walk-free cutting without a pilot hole. Carbide tip provides extended life in porcelain and granite. Pilot bit offers unique grind that starts holes accurately every time.
Works well with smaller hole saws but I used 4 1/4" and it wasn't enough to keep up with the cutting start. It is best to make a small indentation with a small Bosch tile drill (1/8"") and then you have a correct starting point. After that, he holds the saw in the right place to get started. A small carbide burr on the end would probably help. The centering tip breaks if the pressure is too high and does not always ensure a clean start with larger saws.
Pros
Carbide tip provides longer life on porcelain and granite
I bought a Bosch Bi-Metal Hole Saw and this mandrel can't even be attached to the damn thing! It was even recommended to buy both together. It has a hex head of sorts and there is no way to fit or hold standard Bosch bits to it. Nothing to screw on, no rivets. Nothing. Nowhere in the Amazon list are there requirements for what it will and won't work with. This thing seems pretty well made, but make sure it's compatible with your hole saws first.
Pros
Pilot Hole Saw offers a unique finish that starts holes right every time
Typical Bosch tool, this tool is well made and I needed it for the stone hole saw I use. The only problem I had was that the pilot point was not filmed. After the initial start of drilling, it would be advantageous to remove the pilot head as it cannot drill without grooves. This meant that in order to advance the hole saw further than the retracted point, I had to use a drill to poke a hole through the stone, through the center of the core I was trying to remove. This was an extra step thatβ¦
Pros
Retractable shaft allows for no hole cutting without a pilot hole