TR8x8 lead screw to 8mm Nema23 Coupler

This is a very secure coupler for Nema23 steppers, w/ an 8mm shaft, to 8mm 4 start lead screws. The lead screw threads in and then is secured with 3 m3 bolts (20mm - https://www.amazon.com/uxcell-Socket-Machine-Screws-Black/dp/B00W97KM4G/ref=as_li_ss_tl?ie=UTF8&qid=1486386187&sr=8-1&keywords=20mm+m3&linkCode=sl1&tag=wwwbethnchris-20&linkId=6b1551d6a6653efa95aeeaf57d07466f) and nuts (https://www.amazon.com/uxcell-Socket-Machine-Screws-Black/dp/B00W97KM4G/ref=as_li_ss_tl?ie=UTF8&qid=1486386187&sr=