Hole gauges

[dickda1]

Am about to buy some hole gauges again.

I have owned a number of hole gauges over the years from the small hole variety to the telescoping kind.  I can understand paying a premium price for a Mitutoyo or a Starrett micrometer or perhaps even a dial gauge.  But, I have never understood the difference in quality between a $14 set and a $117 set.  I must admit that I have trouble measuring better than about 0.03 millimeters using these devices.  Anyone have any hints on how they use theirs?

-Dick

[picclock]

>> Anyone have any hints on how they use theirs?

Badly ?   

I insert mine at an angle then tighten, then straighten to an upright position to set the width, then angle again to remove.

Never sure if the reading I get is accurate.

If anyone knows a better way I'm all ears.

Best Regards

picclock

[DaveH]

Dick,

It is all about feel.

Dead serious here, practice on  known bore size(s) you will soon get the hang of it.

The difference in price is as always how well they are made. Telescopic ones -easy- allow it to open half way lock it and wiggle it, see how much it moves, allow it to open all the way - lock it and wiggle. Should not wiggle at all. Some wiggle alot more that others. Guess which are the best and cost more.

So there you have it -  

DaveH

[dickda1]

Thanks for the input.  I subscribe to a number of machining/tool forums, but this is where I go for information by people who know what they are doing or are trying (like me).  At some point, given experience and age, I either know it or I don't for this lifetime.

-Didk

[DaveH]

Another way is to make a (or two or three) bore gauge(s) on the lathe – before you start boring.

Let’s say you want a bore dia. 1.000”   make your bore gauge 0.999 – 0.995” dia.

When this bore gauge just goes in ( without wacking it ) you’re there.

You then save that bore gauge for the next time 

This method is a lot more accurate than cheap telescopic gauges.

Go and no go bore gauges are available but can be ooooooh so expensive

DaveH

[BarryG41]

Professional Go - NO Go  gauges are essentially  a production tool.  Yes they are expensive and so is their manufacture.  But there is no need for a hobby builder to make them in HSS and ground to .00001".   Again I would not make them unless you want to go into a semi production of an article.   

A simple and cheap and accurate method is to use internal spring caliper and  a good digital caliper or vernier.   Despite owning M & W ball and spring internal gauges. I generally use the the simple internal spring calipers.

What ever you use, it takes practice to get a good result.

Barry G