I think Kurt held the original patent for the "angle lock" mechanism. Now that the patent has expired, there are dozens of clones. Kurt still sets the standard for milling machine vises. There are some better but they are still based on the Kurt design.
I have a 6" Kurt and a bunch of 6" clones. The Kurt is definitely more accurate and operates much more smoothly. They all hold parts tightly, but the real key to a milling machine vise is its ability to hold parts in a very exact location. From part to part, the Kurt can repeat the location to within a few tenthousandths. The fixed jaw on the clones tends to flex a bit, so they can only repeat to within a few thousandths. The steel and cast iron on the Kurt is also much better and more accurately ground. The beds and jaws on the clones aren't nearly as flat.
The Kurt is worth it if you need the accuracy and reliability. Mine is more than 10 years old and is still more accurate than any of the clones. If the parts aren't so critical, then the clones are just fine (especially at less than half the price!).
Ed Bennett firstname.lastname@example.org http://www.ts-aligner.com
Andrew Barss wrote: