Bore gauge or Telescopic gauge set

blawless · May 18, 2018

Hey fellas, Would you recommend a Bore gauge(Fowler, 1.4 to 6") or the Telescopic set or both? A man can't have enough tools but I think i'm about halfway there.
Bryan

steve-l · May 19, 2018

I don't see that there is a choice. Bore gauges are nice , but require hole standards to calibrate every time you use them. Telescopic gauges are a convenience tool that are only as good as the user. They take a lot of feel to create the measurement consistency that generates your confidence. Plus there are huge differences in telescopic gauge qualities. Then there is the super high dollar 3 legged bore micrometers. They are the best of course, but you need a lot of them to cover your size range and at a $1,000+ a pop, can be pretty much unaffordable. I think you need them all. They fit different requirements.

Red James · May 19, 2018

And if you go with telescope gages, try Mitutoyo instead, not that much more dollars.

thermite · May 19, 2018

steve-l said:
I don't see that there is a choice. Bore gauges are nice , but require hole standards to calibrate every time you use them. Telescopic gauges are a convenience tool that are only as good as the user. They take a lot of feel to create the measurement consistency that generates your confidence. Plus there are huge differences in telescopic gauge qualities. Then there is the super high dollar 3 legged bore micrometers. They are the best of course, but you need a lot of them to cover your size range and at a $1,000+ a pop, can be pretty much unaffordable. I think you need them all. They fit different requirements.

All that and more, gage pins for tiny holes. Flexbar Indi-cal's for grooves & c. too.

Some days one simply fires up the lathe, relies on more-likely to be on-hand OD mics, standards, even gage blocks?

And makes a gauge or set of gages for a specific task nothing else in the box covers very well. Seriously, not that hard to do. If it's a HOLE, something should "just fit" it, right?

RC99 · May 19, 2018

steve-l said:
Bore gauges are nice , but require hole standards to calibrate every time you use them.

Bore gauges do not need hole standards for dial bore gauges, just a bore gauge setting master that uses gauge blocks.

Fowler 73-646- Metric Bore Gage Setting Master Kit 646795172142 | eBay

Limy Sami · May 19, 2018

RC99 said:
Bore gauges do not need hole standards for dial bore gauges, just a bore gauge setting master that uses gauge blocks.

Fowler 73-646-1 Metric Bore Gage Setting Master Kit 646795172142 | eBay

Or a Vernier / digital height gauge on a surface plate.

neilho · May 19, 2018

I do quite a few press fits, usually requiring ID's held to within .0002. Most any gage that can do that works for me. That does not include telescopic gauges, which are useful only for transferring looser tolerance readings. The best I've been able to easure with telescopic gages is mas o meno .001, which is good enough only for large press fits.

Snagged used off Ebay, I have Mitutoyo Holtest 368 series 2 point from .060 - .280, various B&S Intrimics from 1.000 - 3.000 and several 2 point bore gauges for 3-6". By far, my favorite and most frequently used are the Fowler-Bowers 3 point internal mikes, which measure to the bottom of blind holes (Intrimics do not) for .250-1.000 holes. Intrimics measure to .0001, the F-Bs to .0002, which is almost always good enough for me. Interpolation is possible, too.

It seems hard to justify the initial expense of these things, but my third botched press fit convinced me. (Ok, Ok, I'm a slow learner.

) And they're not $1K a pop if bought used. $100-150 is more like it and can be bought one at a time or in sets as they become available.

Clive603 · May 19, 2018

Obtained a couple of allegedly decent bore gauges maybe 15 years ago and have yet to use either! The long stalk makes them a right PIA on the sort of stuff I do. Now maybe if I'd gotten to the Van Norman boring bar set that the second one belonged with before it hit the skip!

Have a complete boxed set of M&W telescopics plus all the small hole gauges which do see regular use. Boxed half set & some odd ones, enough to more than make another set and a couple of Starretts from the "Duuno what these are, can you use them." free shop too.

As always choose your weapons loads to suit what you usually do and improvise when needed. I tend to extend the kit after the third - fifth (ish) improvisation depending on the volume of verbal encouragement needed. Half the time I never need the extra gear again. Which is annoying.

Clive

steve-l · May 19, 2018

RC99 said:
Bore gauges do not need hole standards for dial bore gauges, just a bore gauge setting master that uses gauge blocks.

Fowler 73-646-1 Metric Bore Gage Setting Master Kit 646795172142 | eBay

Your being pedantic. I don't care how you create a standard, you still need one......every time you use a bore gauge and for one, I find it a PIA.

steve-l · May 19, 2018

neilho said:
It seems hard to justify the initial expense of these things, but my third botched press fit convinced me. (Ok, Ok, I'm a slow learner. ) And they're not $1K a pop if bought used. $100-150 is more like it and can be bought one at a time or in sets as they become available.

I admit, I too cannot afford new prices and I shop the auctions as well. I'm still a long way from a complete set, but they are the best.

Limy Sami · May 19, 2018

steve-l said:
Your being pedantic. I don't care how you create a standard, you still need one......every time you use a bore gauge and for one, I find it a PIA.

I completely agree, which is why I reserve dial bore gauges and the like for only when they are strictly necessary.

Leg17 · May 19, 2018

blawless said:
Hey fellas, Would you recommend a Bore gauge(Fowler, 1.4 to 6") or the Telescopic set or both? .....
Bryan

Recommend for what kind of work?
What kind of tolerances?

Mike C. · May 19, 2018

"The best I've been able to easure with telescopic gages is mas o meno .001, which is good enough only for large press fits."

Practice, practice, practice... I use Mitu tele gauges all the time for bearing fits. Just have to learn the feel of both gauges and micrometers. And yes, the Mitu tele gauges are FAR smoother than the cheap chinese ones when going over center in the bore.

neilho · May 20, 2018

Well, yes. That's what I've been told (and believed) for years, that I just needed more practice, but practice is education and education is expensive, certainty less so. Starretts, Mitutoyos, I've used 'em all. F'ed up a lot of work. Maybe it's just me, but I'm not entirely convinced. The last guy that told me he could get the hole size right with telescopics got the job of boring a hole for a largish press fit I didn't have a gage for and it came back a thou over. That mistake cost me enough to have bought the right gage in the first place. Good business lesson, but...

A one off bearing repair job that can be loctited in a pinch? Sure. Use a telescopic. But on a 100% inspected production run, I like being able to throw a gage on a hole, quickly, and have it read a number within .0002" that I can trust. Maybe you can do it with a telescopic, but I bet I can do it faster.

thermite · May 20, 2018

neilho said:
Well, yes. That's what I've been told (and believed) for years, that I just needed more practice, but practice is education and education is expensive, certainty less so. Starretts, Mitutoyos, I've used 'em all. F'ed up a lot of work. Maybe it's just me, but I'm not entirely convinced. The last guy that told me he could get the hole size right with telescopics got the job of boring a hole for a largish press fit I didn't have a gage for and it came back a thou over. That mistake cost me enough to have bought the right gage in the first place. Good business lesson, but...

A one off bearing repair job that can be loctited in a pinch? Sure. Use a telescopic. But on a 100% inspected production run, I like being able to throw a gage on a hole, quickly, and have it read a number within .0002" that I can trust. Maybe you can do it with a telescopic, but I bet I can do it faster.

So much in the tribe of electronics goodies have arrived, many of them programmable, even networkable - that there are far fewer houses making bespoke "mechanical" gages than once were.

That dosn't mean zero. That doesn't mean a modern shop cannot make their own "hybrids". Your frame to fit a specific challenge. Store-bought metrology device. Insure, of course, independent and credentialled calibration with certs. Keep all that up-to-date.

No need to wander about saying: "why doesn't somebody make...".

Just "become" that somebody.

Mike C. · May 20, 2018

" Maybe you can do it with a telescopic, but I bet I can do it faster. "

Maybe with a preset gauge on the same hole, but not if you are inspecting a casting with a few different bearing fits. Virtually my whole day is spent with bearing and seal fits in pumps, including bushing worn fits. Again, just what you get used to.

steve-l · May 20, 2018

Mike C. said:
" Maybe you can do it with a telescopic, but I bet I can do it faster. "

Maybe with a preset gauge on the same hole, but not if you are inspecting a casting with a few different bearing fits. Virtually my whole day is spent with bearing and seal fits in pumps, including bushing worn fits. Again, just what you get used to.

With your example, I would invest in the 3 legged inside micrometers either Mits or Swiss for the sizes you need for sure, but I use Mits telescoping gauges all the time and I am confident in holding size to .001, not so much other brands though like Starret.

Warren · May 21, 2018

don't forget Sunnen

Sunnen products , the hone makers have a nice line up of dial bore gages with rather good and easy mo use set up fixtures available in in several size ranges. Often they can be found used. They may or may not fit your needs, but it might not hurt to have a look.

neilho · May 22, 2018

Mike C. said:
Maybe with a preset gauge on the same hole, but not if you are inspecting a casting with a few different bearing fits. .....

The motions themselves take longer with telescopics. Grab the right gage out of the box (same for both methods) put it in the hole. Telescopics get wiggled back and forth, tilted over center and back, tightened, both motions again to check, pull it out, check it against a mic with the same motions all over. The 3 point internal mics: spin the thimble till it ratchets, read it, pull it out, done. Calibration for both methods is about the same. Both mikes have to be checked against a master occasionally. An internal 3 point mike is just faster and is more reliable, even for different hole sizes.

Can you really measure within .0001" with telescopics? Verifiably?

Leg17 · May 22, 2018

neilho said:
.....
Can you really measure within .0001" with telescopics? Verifiably?

We have yet to see the OP respond to the application intended.

Bore gauge or Telescopic gauge set

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