Adjustable parallels...

I agree with the prior posters; main use is measuring slots; secondary, used as an adjustable gage block. There are two sizes beyond the familiar Starrett set of five. I use them fairly often, but never as a vise parallel. If you want vise parallels, peruse Brown & Sharpe or Starrett on E Bay.
Also very a very useful acessory is hold downs, used to hold workpieces in a mill or shaper vise; they are a strip of hard steel, tapered in it's width and slightly angled on the thick side; one is laid on each side of the workpiece against the vice jaws; when the vise is tightened, the angled back causes them to exert pressure downwards, holding the work tightly against the parallels under the part; they are especially nice under thin work that is difficult to seat tightly in a vise. Starrett sells them in 4 and 6" lengths; for longer work, they can be used in tandem, that is two on each side of the part. I have seen (and have)a set that is 12" long, for use on the shaper, likely home made.
As to the gage block use, another time saving gage is a step gage; I have a pair of them made with steps in 1/16" increments from 1/8" to 1", the first from 1/8" to 9/16", the second from 5/8" to 1". They are especially handy to use in conjunction with the carriage stop in the lathe. My set was made by tool & die apprentices at the Mare Island Naval Shipyard during WW-2; they are made of tool steel and are hardened and ground to close limits. When I sold my business, I left that set for the new owner, and made a set for myself for my retirement shop at home.
 
I like the step gage suggestion.

In my shop, 1 large set of B&S adjustable parallels augments 1 set of Starrett (to 1-3/16", collapsed) and 1 larger set of imported (to 1-3/4") fixed parallels; all cased, and bought, used, on eBay.
 
I don't know what the brand of that adj set at the pawn shop was but they appeared to be brand new. They were perfectly clean and no marks what so ever.

At 35 bucks I probably oughta run back up there and grab em before someone else does.

Thanks for all the input guys,

Wayne
 
I just went out to my shop to look at my adjustable parallels. It is a 6 piece set from Starrett, marked 154-A through F. (.376 to 2.250)

para01.jpg

para02.jpg

Jack

para01.jpg para02.jpg
 
One thing I use them for is if you need to set a sine bar and you don't have gauge blocks, you can set an adjustable parallel to the height you need and use it. I have two sets for when I need two parallels set at an unusual height. Another use is if you have something that is an unusual shape you can use parallels set at different heights and indicate the top of the part to make it level in a grinder or mill. Just some ideas that I use.
 
machinist18 said:
One thing I use them for is if you need to set a sine bar and you don't have gauge blocks, you can set an adjustable parallel to the height you need and use it. I have two sets for when I need two parallels set at an unusual height. Another use is if you have something that is an unusual shape you can use parallels set at different heights and indicate the top of the part to make it level in a grinder or mill. Just some ideas that I use.
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Those are very good ideas. I don't yet have a sine bar BUT that's probably something I'll have down the road. And I hadn't thought about using them to set up unusual shaped workpieces. Very clever!

In school they just teach to the basics, have you make a few things that are pretty easy and if you do it good you get an B. If you do it really really good they give you an A. And if you do extra projects that nobody else in class can do, they give you an award. It's hanging in my bathroom just in case I run out of tp.
In the real world, between engineering gigs, I stood in front of the most poorly maintained bridgport in history with a guy standing over my shoulder wondering why it takes so damn long to find a location. Of course the answer is becuase you could crank the handle 3 full turns before table moved but I digress. And all to run porduction crap. I was the only one who was able to pull off holding dimensions on that pos so I got to set machines up. But never did I get to do anything fancy like what you're talking about where you'd use two different height parallels to get it true.

Good stuff!

Thanks,

Wayne
 
They can be used to measure dovetails by adjusting them between 2 rolls in the dovetail to hold rolls tight against the angles. Then measuring over the rolls with a micrometer.
 
Dovetails like Billh50 wrote.
Mine have a slight radius which makes them handy for measuring ID of holes.

Daryl
MN
 
They can be used to support work like parallels or work that is sticking out from the end of a vise, and on and on.
Many uses beyond measuring slots. They can be stacked on a parallel for a custom height, etc... Many uses. For $35, I would have grabbed the set. You can always sell it fast at that price. What brand were they? The Starrett set is the best, well made and coveted.
 
Another similar device is the Brown & Sharpe tapered parallels; they are made to measure holes rather than slots; they have one flat edge and one radiused end, and are not attached to one another like adjustable parallels, they are selected for the range of size to be measured, one is inserted in the hole with its small end projecting out of the hole, then the other one is inserted with big end out, wedged in place and measured with a micrometer. I see them on E Bay occasionally, and they are not generally a big ticket item.
 
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