1" Copper Helix bit
To install , consult with the owners manual for your grinder.
Lubricate the bit before putting it on the shaft. If the Grinder is idle for more than a week remove the grinder bit, this will ensure the bit does not fuse to the shaft. It will also give you the opportunity to inspect the shaft and bits and apply lubricant regularly.
You can use Vaseline as a lubricant.
Always wear safety glasses when in use or changing bit and keep away from children.