Precision Parallel Set: How accurate do a set do I need?

EmilioG

EmilioG

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Precision Parallel Set: How accurate of a set do I need?

I'm shopping for a good set of thin parallels. I see them on Ebay, Enco, etc...
The Brown and Sharpe set looks nice but pricey. I don't do too much ultra precision
milling/drilling, but whatever will make the parts better. How much do most
people spend on a set of 1/8" parallel sets? Does it make sense to spend $200-$300.00?
Thanks
 
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Airplane parts or wheelbarrow parts? Drill vise or a finely machined kurt vise? If you do not have a vise that is parallel to your mill table with in tenths save your money. Imports, HSS tool bits, Starrett hardened and ground flat stock, or mill some up out of flat bar. These will get you with in tenths to a few thousandths for a mere fraction of a $200.-$300.00 set. If on the other hand you need absolute precision Suburban Tool, Starrett, or old Brown & Sharpe parallels but we are talking aerospace quality now.

Regards
Darrell
 
A $30 - $50 set should do fine for a hobby machinist. I bought a set for $50 from a retired machinist 20 years ago. It is the only set I have ever owned. I reground them once when I got my surface grinder a couple of years ago.

Randy
 
I bought a HF set for 22$, with coupon. They seem of good quality and mic out fine. I couldn't do better for the price, for my hobby needs.
 
Thin parallel sets are 1/16" thick, while most standard sets come in either 1/8" or 1/4" thick. Absolute sizes are nominal. For example, a 1/2" pair may measure 1/2" tall +/- a few thou but each parallel in a pair of a given height will have been ground together and should be of identical height.

Unless you plan to do precision measurements with them an imported set will do fine for general work.
 
I also have the HF 1/8" set. When I first got them I took them to work to check them out As we had a surface grinder if thay where out . But on a ferry large serface plate that had just been re certifyed thay where all within .0001 can't ask for much better.
 
EmilioG said:
I'm shopping for a good set of thin parallels. I see them on Ebay, Enco, etc...
The Brown and Sharpe set looks nice but pricey. I don't do too much ultra precision
milling/drilling, but whatever will make the parts better. How much do most
people spend on a set of 1/8" parallel sets? Does it make sense to spend $200-$300.00?
Thanks
Click to expand...

This was a question I had to answer for myself. Just to become familiar with mills and lathes I was ok with just changing the shape of a piece of metal. One of my first projects was to mill a non standard 1911 front sight to match a non-standard rear sight that was on one of my pistols. I am on my 5th attempt but have found that I have had to use better and more accurate methods and aids to even get close to something I find acceptable.
So for me when I use the best, I at least know the fault is not in the equipment but rather in my own skills.
 
18w said:
Airplane parts or wheelbarrow parts? Drill vise or a finely machined kurt vise? If you do not have a vise that is parallel to your mill table with in tenths save your money. Imports, HSS tool bits, Starrett hardened and ground flat stock, or mill some up out of flat bar. These will get you with in tenths to a few thousandths for a mere fraction of a $200.-$300.00 set. If on the other hand you need absolute precision Suburban Tool, Starrett, or old Brown & Sharpe parallels but we are talking aerospace quality now.

Regards
Darrell
Click to expand...

Emilio, I hope my above comments didn't come across as being a smart a$$. Doing the most accurate work you can is the basis of machine work whether you are a hobby person or a pro. There are all different kinds of needs and levels of accuracy however. The quality of imported parallels is remarkably good...yes there are some clunkers. This hobby can suck your wallet dry in a hurry and I think the average home shop guy can waste a lot of money "chasing tenths" when so many other factors such as the machines themselves, vises and inaccurate setups contribute to dimensional error. I don't want to dissuade you from buying quality tools but I think you would be served well with the imports. With the money saved keep your eye out for a retiring toolmaker, or there is a ebay seller who specializes in used tooling that he regrinds, and buy yourself a couple of different pairs of really fine, accurate parallels that you keep tucked away for those special jobs. Ultimately your imports may be just as accurate but there is also a sense of pleasure and pride using certain tools when a particular job requires the utmost in accuracy.

Regards
Darrell
 
I have a set of parallels that cost about £40 , their realy quite good and came in a nice box.

somone else pointed out that it all adds up, table, vice, parallels, head alignment etc.

i might cry if i ran a cutter into a £150 parallel :)

Stuart
 
If you just need two pieces of metal at the same height to support your project. Then IMHO an import parallel set will me more than adequate. They will probably be ground in sets, so will be matched. BUT, do not expect them to be set/ground accurately at a nominal dimension. Now, if you want parallels and you want to do quantitative measurements with them, then dig into your wallet. If you want a ½” parallel to mike 0.500” it will cost you…Good Luck, Dave
 
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