Warped Parallels

I recently bought a pair of cheap parallels from MSC, and after about 1 month of use, many of them have become warped. I'm trying to determine whether this is because I bought a POS product, or because of something I've done wrong.

When I clamp a work piece in my vice using the parallels, I'll tap the piece down with a rawhide hammer to ensure that there is no clearance. I wouldn't expect this to warp a piece of hardened steal, but who knows.

Anyone experience a problem like this before? These are the parallels in question, fyi

1/8 In. Thin Style, 10 Pair Parallel Sets - Thin Parallel Sets | MSCDirect.com

:violin:$87.00 for parallels that are warped? I'm sorry, but you got hosed. I got my parallels from a local Chinese guy for $29.00 and have had absolutely no problem with them.

I used to make my own parallels, but for $29.00 I couldn't even buy the steel.

I use a steel hammer and a block of oak to hammer my stock down, I have done this for years and no problems.
Maybe you could post a picture so we can see whats going on?

I have sets of Chinese parallels in 1/4" and 1/8" that I've used for the past 8 or 10 years, no problem (except that they are only parallel w/i ~ half a thou as they were from the day I bought them. I've had good intentions to grind them, but as with my other good intentions, never got around to it.

John

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Originally Posted by JohnToner

I have sets of Chinese parallels in 1/4" and 1/8" that I've used for the past 8 or 10 years, no problem (except that they are only parallel w/i ~ half a thou as they were from the day I bought them. I've had good intentions to grind them, but as with my other good intentions, never got around to it.

John

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Those "Roundtuits" are hard to find I must admit ha!

The 5/8" parallels have bowed by about 15-20 thou in the middle (image below), and I have no idea how. The weird part is that they were all fine out of the box, but after very minimal use, they are completely out of whack.

Does anyone have any thoughts on 1/8" vs 1/4" parallels? Most of my work is rather small, so 1/8" parallels seem to make more sense, but I'd rather not waste my money if they'll just warp like my old ones.

https://mail-attachment.googleuserco...SSb7QRaqJVISiY

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Originally Posted by FuriousGeorge

The 5/8" parallels have bowed by about 15-20 thou in the middle (image below), and I have no idea how. The weird part is that they were all fine out of the box, but after very minimal use, they are completely out of whack.

Does anyone have any thoughts on 1/8" vs 1/4" parallels? Most of my work is rather small, so 1/8" parallels seem to make more sense, but I'd rather not waste my money if they'll just warp like my old ones.

https://mail-attachment.googleuserco...SSb7QRaqJVISiY

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The pic didnt come thru George.
If they are out edgeways you would have to do some super hammering to bend them in that direction. I could see it if there was something in the vise under the parallel when it was hammered down.
I make sure everything is clean and that they sit square to the stock before clampning, then hit the part to seat it. Are there any visible dings in the surface of them?
What are you using to check them, that needs to be a machined surface mill table etc.

George,

Harbor freight parallels ?

Mike,

Sorry about that, lets see if this pic works. There are a few minor scratches in them, but no major dings. My guess is that some grit got between them when I put them back in there case. Maybe not the best scenario, but I certainly wouldn't expect it to warp a parallel to the degree I'm seeing.

I have measured them by placing them on a stone, holding down the ends and putting a feeler gauge under the middle. Some are as much as 8 thou off this way, which is totally unacceptable.

[IMG]http://i1280.photobucket.com/albums/...psede686d3.jpg[/IMG]

twocik,

I wish I got harbor freight parallels, maybe they still woulda warped, but I would have been out a bit less money!

In my experience it is not uncommon for 1/8" parallels to be bowed about the vertical axis as they are not intended to be used laying down. How straight and parallel are they when standing up? Thats what really matters.

-Dan

I'm not sure why you'd care about them being bent a few thou in that direction. What you care about is that they are straight in the OTHER direction, as that is how they're typically used.

Regards,
Ray L.

They are just bowed a bit, I thought you were talking about the other direction.
Parallels are meant to be used on edge not flat, or at least I have never used them on the flat side.

This is the parallels page on the Shars website.

shars.com

They have several thickness listed.

You should be able to take the bow out of yours by hand.

I didnt check but I dont think mine are hardened.

George,
The guys are right, you're ok. I have a set that are bowed the same way, purchased from one of the cheaper companies. Can't beat that 20% on top of a sales price.:cheers: The only thing to watch out for is drilling holes or tapping on them. I leave about .140" of wall clearance or more. Look at it as saving money on a set of wavy parallels. :)

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Originally Posted by FuriousGeorge

Mike,

Sorry about that, lets see if this pic works. There are a few minor scratches in them, but no major dings. My guess is that some grit got between them when I put them back in there case. Maybe not the best scenario, but I certainly wouldn't expect it to warp a parallel to the degree I'm seeing.

I have measured them by placing them on a stone, holding down the ends and putting a feeler gauge under the middle. Some are as much as 8 thou off this way, which is totally unacceptable.

[IMG]http://i1280.photobucket.com/albums/...psede686d3.jpg[/IMG]

twocik,

I wish I got harbor freight parallels, maybe they still woulda warped, but I would have been out a bit less money!

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You can put a spring between them that will serve a dual purpose. It will straighten them out and it will hold them in place.