Here in Japan I use primarily Mitutoyo and NSK. Both my inside micrometer sets allow me to chain the sections together so I can measure up to 500mm. You can buy additional sections that add on as well. The precision is kept because the outer cylinder is only support, there is an inner floating rod that is precision ground and spring loaded and directly contacts the measured surfaces. That Starrett design seems limited by using the rod itself (and the threads!) as the gauge, and having the tips of those sections semi-fixed looks like a pain for chaining them. The ones I have don't require a seperate end piece that may get lost, incorrectly tensioned or attached to the wrong unit that it's not calibrated for. I have some Starrett items, and they are good (although oddly rust prone), but I'll take a Mitutoyo over them whenever possible.
Presumably the threads aren't actually used for setting the length. One presumes that the flat surfaces set the length and the threads provide preload effectively.
@@zyeborm That makes sense, but it's still very susceptible to any kind of contamination that gets in between the landings where it is hard to see or if the thread isn't fully tightened. With the style I have all reference surfaces are exposed and the threads are not part of the equation. The fact you can mix and match all the pieces without any tools or extra steps is a clear advantage, with the micron precision set they offer better thermal isolation as well.
I have this set. However I often use snap guages and mics to fit parts. That way I measure both ID and OD with the same tool. Eliminating errors caused by different calibrations..
Things of beauty, joy for ever. I've got a Starrett automatic center punch. It's a bit finicky and worn, but still works. Not sure how many holes I marked with it.
But if you have a set of outside mics, just get a set of small hole/telescoping gauges (Mitutoyo 154, 155). Not as precise or pretty but a lot cheaper and easier to use. For pretty, I'd suggest a Starrett 359 Precision Universal Bevel Vernier Protractor. Only a grand each! The acute angle attachment is $120 more.
