Review on 🔧 Precision Milling Arbors Mandrels - Enhanced Expansion for Optimal Performance by Will Anderson

I bought these to compare with products that are 2-3 times more expensive. I was surprised. I only needed 7/8". It showed a TIR runout of 0.00015 when assembled on a new milling machine with about the same TIR. The cone on the head of the jackbolt had the same runout and was very smooth, ground. appeared to have been carved on the steps of a staircase. Unusable. But it took me about 3 minutes, spinning on my lathe against a small 200 grit cone sander in my Dremel to smooth it out to perfection. Then I found that the Carving for the expansion screw was full of metal shavings and debris The 6 x 1.0mm bottom tap was manually pierced to clean it worked great after about 20 minutes of very light work It is a poorly finished product typical junk which comes from China, but it's made to real size and will almost effortlessly fit just about anything you'll ever need or find anywhere else in. Do other expensive US-made devices that a e promised next day delivery, took 2 weeks to get here.