I used stainless screws on a fixture that required frequent loosening and tightening. After about 25 cycles the stainless screws broke. The steel screws hold up better to the stress.
In an engine where they get put in and out a few times they would work out great but a tool holder where you cycle that screw in and out, it might not hold up.
Good point Steve, thanks! I will reserve the stainless screws for the holders that rarely get changed like dedicated knurling tools and such. I have material on hand to make a total of 21 holders so frequent swapping won't be a big issue I hope. :big:
Use 'em till something breaks. Tapped holes in AL will fairly quickly wear out if used repeatedly but you can always put an insert in there so I say get some use out of them first.