When it comes to buying an extra long bit like the one required to do the job, you're not going to have much choice between "cheap" or "premium". FWIW, the one I bought back in 1974 has served me well and is still in fine shape to do many more blocks. But I should note that I have never used that bit for anything else.

Last edited by Stanton; 09/08/19 10:16 PM.