Miniature bench grinder

[wizard69]

Probably not. Those were supplied with the kit and I built this many years ago before I had the ability to make hex head bolts that small. I should go back and do that the next time I find a round toit in the tool box.

You might be surprised to find that a lot of machinery from that era had part held together with slotted head screws. I can remember back in the 1970's, when I just entered industry, a manual Pratt & Whitney profile mill constructed with such screws. I didn't see a lot of equipment of that age and frankly I was kinda surprised even back then to see a machine assembled with such bolts. In one case we had to resort to a modified drag link socket to break the screw loose.

Early screw threads and bolt forms are a very interesting subject, The Sellers Thread form took a while to become industry standard driven largely by the Pennsylvania Railroad and Baldwin Locomotive works. Sadly it took the horrors of WW2 to get the "English" thread forms on a common standard, so pre WW2 machinery had all sorts of bolts and screws we don't see today.

I find the whole subject of screws to be very interesting. It literally took 70 years for the Sellers thread form to come around and then almost as long to get the standards we have today.