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How warped are your parallels?

F35Machinist

Cast Iron
Joined
Nov 3, 2021
Location
California
I have a few sets of cheap 1/8" thick chinese import parallels and they all measure within .0002" of nominal height. Thickness is also uniform within each individual piece, however they are all warped by at least .020". This creates a problem where chips get in between the parallel and the vise jaws. I would buy more expensive brand name sets, but I'm not sure they would be any better? Is there any brand out there that I can buy that is just as accurate in height and doesn't have the warp?
 
None of mine are warped, but they are all probably at least 15+ years old and big name brands. I bought or received most of mine secondhand from guys who were retiring and such.
 
I've had access to at least four sets of cheap Chinese import parallels recently and none of them are warped by 0.02". Most of them are flat enough that the pairs will cling together when wet with a film of WD-40. Even so, when I am swapping parts manually, I make a point to clean both the parallels and the vise bed and jaw faces when (re)placing the parallels.
If you have a production job, find a way to secure the parallels to the jaws so chips don't get into the horizontal contact faces. It doesn't matter very much (if any) if chips get in between the vertical faces. Consider "wavy" parallels.
 
I've gone through several sets of cheap 1/4" thick parallels and they are inconsistent. Heights vary by as much as .0008", bent along the length a bit (not .020", maybe .010"), working (horizontal) surfaces not perpendicular to the vertical surfaces, etc.. Also the cheap ones seem very soft -- they get little dings on the edges with the slightest contact, which translates to an ugly scratch on the part when you slide the part against the work stop.

The challenge for me is justifying the much higher cost of "very good" parallels, and, tothe OP's point, maybe they wouldn't be much better.

Regards.

Mike
 
This is silly. If you’re fine with buying bottom of the barrel products, then you should be fine with the tolerances. If you’re really unhappy, buy a few more sets to select good from bad or pony up and support the few remaining good brands that won’t send you warp tools. Just my opinion of course
 
I've never seen any warped. 020 either. At least the important way is within .0002. That is good!

No worries. Straighten them in the vise. On each end put an equal thickness spacer against the fixed jaw. Super glue them so they won't move. Glue another block in the middle of the moveable jaw. Put a parallel in there and deflect it to a gauge pin. Use smaller pins until the parallel is straight.

If they are all warped about the same, then same deflection should straighten them.
 
Our cheap Shars set is warped like that too. No complaints though, they are fine height wise which is the important part.
I wasn't expecting perfection for $30. I think a "regular" set is around $200 now?
 
I have a few sets of cheap 1/8" thick chinese import parallels and they all measure within .0002" of nominal height. Thickness is also uniform within each individual piece, however they are all warped by at least .020". This creates a problem where chips get in between the parallel and the vise jaws. I would buy more expensive brand name sets, but I'm not sure they would be any better? Is there any brand out there that I can buy that is just as accurate in height and doesn't have the warp?
If you bought a more expensive name brand set it would most definitely be better.
 
This doesn't address warped parallels, but the problem of holding the parallels against the jaws.

Get one of these. They work great, and are not too spendy.


Even better, these thing are the absolute tits! I was lucky and got a 6" set fairly cheap. The angle parallels are very handy.

 
I have 17 sets of 1/8" parallels. Sixteen I assume are Chinese (Shars) and my first set I ever bought 20 years ago as Brown and Sharp. The B & S are the worst as far as being close to nominal, and no better at all in parallelism. They were also four times the cost 20 years ago to what I can by the cheap ones for now. A lot to pay for a touch better fit and finish, which is all the B & S had above the others. Sad.
 
These days, and even 20 years ago, paying more for a name doesn't automatically mean better. Even worse, that name may be made in the same place as the cheap ones.

Keep old hose that's not in terrible shape to cut into custom lengths as parallel keepers. This works really well for shorter vise openings, and if the hose is stiff enough it'll force the parallels straight.
 
We have 1/8, 1/4 and 1/2" Chinese parallels. The 1/8" do have a curve to them, 1/4 and 1/2 are much more flat. 1/4" are most commonly used. My Starrett set is flat and parallel on all side but only comes out for special occasions.

Don't really have an issue with chips getting behind when using metal pallet strapping as parallel keepers....
 
I have cheap ones also, Shars also, yeah they are warped.
If I cared, what I have done in the past, I put them in with the ends bowed out,
and I have urethane straps that I use to hold them in and back.

But if I need parallels for a one off, I use them, pull them out, or in and out a couple times,
like sfriedberg, I pull them out and clean between each time.

If I'm doing production, worried about chips behind or under I use hard or soft jaws.

In my mind there is no such thing as production work with parallels.
 
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I have 17 sets of 1/8" parallels. Sixteen I assume are Chinese (Shars) and my first set I ever bought 20 years ago as Brown and Sharp. The B & S are the worst as far as being close to nominal, and no better at all in parallelism. They were also four times the cost 20 years ago to what I can by the cheap ones for now. A lot to pay for a touch better fit and finish, which is all the B & S had above the others. Sad.

If they were that bad, why didn't you return them? I have two sets of B&S and they are both within a couple tenths to nominal and dead parallel.
 
If they were that bad, why didn't you return them? I have two sets of B&S and they are both within a couple tenths to nominal and dead parallel.
They weren't that bad per say, I just found out years later that you don't need to pay four times the price to get something comparable. Most of my Shars ones are within a couple tenths. 20 years ago I was pretty green, and didn't think that being under nominal 2-3 thou was a thing, which most of the time it's not.

I have a about a dozen large B & S parallels (1 X 2 X 12 and larger) that are likely 50 years old or better that are insanely good. I'll use them for anything, including setups in rebuilding machines etc. The great thing is I got the whole lot at auction for 80- bucks years ago when you stood around all day in person. They looked like a box of steel bars under a table. I knew better, even way back then. :-)
 
I have cheap ones also, Shars also, yeah they are warped.
If I cared, what I have done in the past, I put them in with the ends bowed out,
and I have urethane straps that I use to hold them in and back.

But if I need parallels for a one off, I use them, pull them out, or in and out a couple times,
like sfriedberg, I pull them out and clean between each time.

If I'm doing production, worried about chips behind or under I use hard or soft jaws.

In my mind there is no such thing as production work with parallels.
I use pieces of metal bander material formed into a z to keep mine from moving. I prefer step jaws as well for production. So much easier to clean and go.
 








 
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