Plug gages and comparative depth gages...

[tmac1956]

All:

I've been looking at Enco for these to tools, but I don't want to spend too much, or on the other hand, buy junk. Does anyone have any recommendations?
(I've been reading George Daniels book "Watchmaking")

Thanks!
tmac

[tmac1956]

Well, I think probably need to re-phrase the question. Regarding the plug gauges... they come in what I believe to be a minus tolerance and a positive tolerance. So which do I need?

Thanks in advance!

tmac

[gerene]

Maybe I completely misunderstood you and/or Daniels but the way I read Daniels he talks about making your own plug gauges either tapered or parallel.
For tapered gauges he suggests marking them in convenient intervals after measuring with a micrometer, whilst for standard diameters he suggests parallel gauges turned down to the full diameter of the jewel and then to reduce one end to two smaller diameters.

I tried to find what you where looking at buying but could not find your supplier (lots of enco companies but none relevant).

Again if this is not what you where referring to then I apologize (only a beginner).

Jan

[tmac1956]

[Bob Tascione]

Hi Tom,
Yes you're correct about having to do with the tolerances. If you're talking about the ENCO Class ZZ Steel Pin Gage Sets then the minus tolerance set would mean that the pin 'should not' exceed the stated diameter but could fall under the stated size by -0.0002. So as an example a pin that is say .030 dia. would not exceed .030 but could fall below .0002 to .0298. The Plus Tolerance sets would be just the opposite. In many machine shops and most tool rooms you'll find both sets on hand but given the choice of just one set I prefer the minus tolerance set. Just my personal preference though.

Hope this helps Tom,
Bob

[tmac1956]

[david pierce]

Tom,
The sizes you need depend on the hole diameters you need to measure. For watches this means small sizes. Most of the watch pivots I measured are around .004 inches or .1mm. The sets start at .o1 inches so you will have to purchase or make the smaller sizes. The reason for the minus and plus sizes is the measurement process is done with with the GO/NO GO technique. If the small gauge goes through the hole and the large size does not, the diameter of the hole lies between the two gauge sizes. This means that in order to get the proper use from the gauges, both the minus and plus sizes are needed.
david

[tmac1956]

[Bob Tascione]

Sorry Tom,
I read your response to my post immediately after you posted (I was online when you were posting) and the question about what sizes to get wasn't there. You must have edited and added that question to the post a little later. Anyway looks like David got you covered ok.
Enjoy,
Bob

[tmac1956]