Pin Gages?

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SteveHGraham
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Pin Gages?

Post by SteveHGraham »

I was watching an Abom79 video in which he used some cheap pin gages a viewer sent him. They were so cheap, they weren't even hardened. Anyway, it's a tool I have never used.

Wondering what people think of these. Good to have around? Seems awfully similar to a telescoping gage, without the ability to get between thousandths. On the other hand, they come in sizes too small for a telescoping gage. Also, I suppose a pin gage would give you some indication of whether a hole was round and whether it had irregularities obstructing it.

Shars sells a huge set of small ones, hardened, for $39. I know some people buy drill rod indices. Kind of seems like the pin gages might be a better deal.
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earlgo
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Re: Pin Gages?

Post by earlgo »

Pin gages imply at least a couple of different things.
1) your stuff is going to be inspected by a 3rd party
2) you will need a set of reamers
My stuff is never complicated enough to require gages, although I do have an incomplete set of Van Keurin gage blocks that I got for free. I rarely use them for the above reason. I do use them occasionally to set the table saw depth and send pics to my buddy just to hear him fume. :twisted:
Others may have reasons to have pin gages, but I never once have wished for them
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SteveHGraham
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Re: Pin Gages?

Post by SteveHGraham »

I am guessing they are not all that useful on drilled holes, right? But on the other hand, drill rods wouldn't be useful, either, since they're also perfectly round. And drill rods are more expensive.
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BadDog
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Re: Pin Gages?

Post by BadDog »

I've got pin gauges and use them every once in a while to accurately figure out hole sizes, or to measure across for center line dimensions. Most often just to calibrate a micrometer, and my "feel". But so far not something I use regularly, or couldn't live without.
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mklotz
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Re: Pin Gages?

Post by mklotz »

Where will you find a telescoping (or split ball) gauge that will measure the size of holes smaller than 1/8"?

They're my tool of choice for holes that fall below that size. With larger holes, one has the problem of telescoping/split ball gauges requiring the operator to develop a "feel" for using the tool. Pin gauges remove the reliance on operator dexterity.

Incidentally, the range of hole sizes that can be measured can be extended beyond the largest pin in the set by using three pins together. This is a consequence of the geometric fact that, if you have three circles, each tangent to the other two, a tangent circle (the outer Soddy circle) can be drawn around them.

More detail on this can be found here...

http://www.homemadetools.net/forum/sodd ... ages-27355
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Inspector
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Re: Pin Gages?

Post by Inspector »

I used to use them a lot when inspecting. Great way to have go/not go measuring capabilities when you don't have a specially made one for a job as long as you keep in mind what kind of set you are using. A minus set, plus set or a nominal set. You can also see very quickly if a hole is tapered along the length. There was another member that had written a spreadsheet for using three pins to measure a hole as Marv mentioned above. I tried to get a guy to write an app for my phone so I could do it at work but that didn't pan out, and because we weren't aloud to download to work computers I could never take advantage of that measuring method. When a little cash builds up in the disposable account I'll buy some sets of gauge pins to use at my lathe and mill.

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John Evans
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Re: Pin Gages?

Post by John Evans »

Well I fell into a bunch the first of the year from .060 to 1" . Missing a few but sold off the duplicate sets so cost on what I kept is close to 0. Matter of fact just used some yesterday to confirm the size of a hole I need to make a sleeve for. Another option is get a set of " Tapered Parallels", my B&S set covers .25 to 1" . Those you use 2 of wedged in the hole and read with a regular OD mic. Of course that does not tell you if the hole is out of round-tapered etc. Horses for courses !!
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whateg0
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Re: Pin Gages?

Post by whateg0 »

In the video he was measuring a hole with an oil groove that wound its way through. That is a good application for a pin gage. There might not be enough smooth continuous surface to sweep a telescoping gage for an accurate measurement. Similarly, on a thin part with a hole, where again there's not enough material to sweep a telescoping gage, a pin gage can be dropped in.

I would like to have a set of gage blocks, but for most things I need to do, I use a set of adjustable parallels, measured with the mic after tightening to get the sizes I need. I don't have anybody inspecting my work, though. None of my mics have been calibrated since I bought them, and none of them have arrived with standards, so I use a 1-2-3 block that I checked with a calibrated mic at work.
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Re: Pin Gages?

Post by whateg0 »

John Evans wrote:Well I fell into a bunch the first of the year from .060 to 1" . Missing a few but sold off the duplicate sets so cost on what I kept is close to 0. Matter of fact just used some yesterday to confirm the size of a hole I need to make a sleeve for. Another option is get a set of " Tapered Parallels", my B&S set covers .25 to 1" . Those you use 2 of wedged in the hole and read with a regular OD mic. Of course that does not tell you if the hole is out of round-tapered etc. Horses for courses !!
Do they make adjustable parallels with rounded edges? All of mine are square, so to use them in a hole, I'd have to put a dowel on each edge.

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BadDog
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Re: Pin Gages?

Post by BadDog »

They do. The only one I know is B&S (672) who make the adjustable hole parallels. But they don't dovetail together like typical adjustable parallels.

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Magicniner
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Re: Pin Gages?

Post by Magicniner »

mklotz wrote:Where will you find a telescoping (or split ball) gauge that will measure the size of holes smaller than 1/8"?
I picked up a Diaguage split ball set which goes down a little below 40 thou for £50 last year, hardly used and with all the reference rings present, if you know how to set these up with a digital indicator they give direct ID readings on the gauge ;-)

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SteveM
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Re: Pin Gages?

Post by SteveM »

One of the questions that pin gauges will answer that using a mic, small hole gauges and calipers will not:
How large a round pin will fit in the hole?

If you drill a hole and it comes out three-lobed (not an unlikely occurrence) , you can measure until you are blue in the face, but the measurement you come out with will be larger than the size you get with a pin gauge.

To illustrate: think of the worst three-lobed hole you could have: a triangle. The measurement you will get will be the height of the triangle, when what you really want is the inscribed circle. It's an exaggeration, but I think it gets the point across.

Steve
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