Parallel Clamps Question

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Forum topic by unclearthur posted 12-20-2013 05:35 PM 1183 views 0 times favorited 8 replies Add to Favorites Watch
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383 posts in 2864 days

12-20-2013 05:35 PM

Topic tags/keywords: parallel clamps

This may be a stupid question but …...

Today I bought some parallel clamps (my first) and when I got home I noticed that the fixed jaw was not square to the bar on any of the clamps. Some are pretty close, others are significantly off.

Previously I had thought the whole point of parallel clamps was that the two jaws were each square to the bar and parallel to each other.

Have I bought junk that needs to be returned or am I missing something here?

Thanks for any replies.

More info: The distance from the top of the bar to the top of the fixed jaw is just under 4”. Over that distance the jaw is out of square on most of them by 1/64” – 1/32”. On a couple of shorter (12”) clamps it is worse (1/16” – 3/32”).

8 replies so far

View Paul Mayer's profile

Paul Mayer

1154 posts in 4142 days

#1 posted 12-20-2013 05:39 PM

1/64” doesn’t seem problematic, but 3/32” sounds pretty bad to me. I have never checked mine, but now of course I will.

-- Paul Mayer,

View bigblockyeti's profile


7250 posts in 2797 days

#2 posted 12-20-2013 05:40 PM

The only stupid question is the one that is not asked. You didn’t mention what make and model the clamps were. In my experience, expensive ones will be square to the bar, moderately priced ones can be hit or miss, cheap ones usually not.

-- "Lack of effort will result in failure with amazing predictability" - Me

View Loren's profile


11190 posts in 4724 days

#3 posted 12-20-2013 06:04 PM

Clamp something up under substantial pressure and check parallel
under load.

View Fred Hargis's profile

Fred Hargis

6967 posts in 3570 days

#4 posted 12-20-2013 06:53 PM

I checked mine since this came up on another forum a week or two ago. My Besseys are not square, but squeeze something together and you find the bar will flex in a way that makes them square to the corner of the workpiece; somewhere I read they are designed to be that way. My Jorgy’s are square to the bar. The Jorgy bar is a little more robust than the Bessey, so maybe it doesn’t flex as much (?), just guessing here. Regardless, I get excellent results with both and am not concerned about it one way or the other.

-- Our village hasn't lost it's idiot, he was elected to congress.

View pintodeluxe's profile


6370 posts in 3890 days

#5 posted 12-20-2013 07:02 PM

Most parallel clamps have a built in angle. They look slightly crooked when not in use, but straighten out when pressure is applied. Ultimately, when clamping up panels you will still want clamps on top and bottom. I have found I can adjust the clamping pressure top or bottom until the panel checks flat to a straightedge.

Test them out, and see how they perform.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View unclearthur's profile


383 posts in 2864 days

#6 posted 12-20-2013 07:45 PM

I thought abut the built in angle issue, but in this case the angle seems to vary from clamp to clamp so I’m not sure it is intentional, or if it is then the quality control isn’t great.

I confess, these are a discount brnd about 1/3 the cost of Besseys. Identical overall dimensions and appearance. Have to decide whether to return them and stick with F clamps or ‘good enough’. Can’t afford the real McKoy.

View JonHitThingWithRock's profile


97 posts in 2799 days

#7 posted 12-21-2013 03:47 AM

i have a couple jorgensens and a couple irwins, the jorgensens are perfect, the irwins are not even close, plus the grips spin independently of the tightening mechanism, so pretty much garbage, if you’re looking for cheap clamps, bar clamps are excellent, and you can even go with a good brand and not spend very much, the only problem is the small clamping surface, I’ve found those to be pretty square to the bar (at least jorgensens are), i find myself, overall, using f clamps way more than parallel clamps, and you can get a carfull of f-clamps for the cost of 2 parallel clamps

View paxorion's profile


1107 posts in 3122 days

#8 posted 12-21-2013 01:14 PM

The inconsistency sounds like a manufacturing defect or poor quality control. What brand are they? And it may be worth raising this up with customer service/tech support if that is an option.

-- paxorion

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