Re: Dumb question dept. - and what about the Unimat grub screw
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You're looking for M6 DIN 417 grub screws for the front of the tailstock and for the headstock. Normal dog points won't work!
On Wed, 30 Aug 2023, 09:51 Herman de Leeuw via , <herman.deleeuw= [email protected]> wrote:
Thanks for the fascinating discussion. If I may, what would be the advice for the grub screws that are found on the Unimats? Which form should these have? So far, I believe mine (for drilling head and tail stock) to be flat with some 3 mm of thread removed.
Herman
Thanks in advance?
Yes the typical smaller screws are cold formed. The end of the screw shows what happens when a formed thread is not supported. Those smaller screws are squished between 2 plates with slanted grooves. That is what forms the threads. When the cylindrical shank is squished some of the material deforms out of the end of the screws. If the screw has a squished looking end it was cold formed. If it is perfectly flat with a chamfer then it is machined out of bar stock. Usually over 1¡± are machined.?
Under a 1/4¡± are made on high speed machines, 1/4-7/8¡± are on larger former machines and 1¡± and over are usually machined. That is why pricing changes quite drastically around those sizes.?
If you look carefully, many bolts are not actually flat on the end.? At times I have had to machine the end of a screw flat to not have marring.
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