Hello

It is possible to buy pliers that have genuinely parallel jaws which can be locked like a pair of Mole self-grip pliers?

i.e. I am looking for a fusion between:

A)

and

B)

I want completely parallel sides so as not to damage the part.

The nearest I could find was this:



But firstly, I don't want that cumbersome sticking out leg (although if pushed I suppose I could cut it off!)...




...but more importantly, the jaws rotating towards each other rather than moving in parallel towards each other.

J

Edited By John Smith 47 on 05/05/2021 18:14:50

Edited By John Smith 47 on 05/05/2021 18:15:24

Why not drill the handles of photo 1 and fit a threaded bar arrangement or a cam?

Please see if any of these come close to your requirements. The last one in the list is stretching the specification a little.

https://www.toolsntoolsuk.co.uk/shop/parallel-action-locking-pliers-jewelry-craft-hand-vise-smooth-flat-brass-jaws-6/

https://www.misterworker.com/en-gb/stahlwille/parallel-jaw-self-grip-wrench-6562/8994.html

https://www.tooltique.co.uk/shop/vintage-speetog-parallel-jaw-adjustable-locking-plier-clamp-good-condition/

https://www.riogrande.com/product/swanstrom-self-locking-parallel-action-pliers/111649

https://www.cromwell.co.uk/shop/hand-tools/locking-pliers-and-grips/255mm-10inch-parallel-plus-grip-wrench/p/KEN5587250K

If you get stuck then compress two 3mm plates in molegrips and tack weld them on

Deleted because I typed a bit slower than others.

Martin C

Edited By Martin Connelly on 05/05/2021 18:39:57

I have a couple of parallel jawed pliers that lock onto the item being gripped. They are called Speetog plier clamps and they look like this;

The screw on top closes the jaw and determined the amount of holding force.

They don't appear to be made any more but sometimes turn up on ebay etc.

Brian

I've had a CK Parallel-Grip Perfect for many years which does have true parallel jaw movement but only a sliding sleeve to set size relying on friction to hold it in place. Grip is decent but not as good as the real thing. Appears to be discontinued.

The Stahlwille 65622250 in the misterworker link from DC31k has the same pivot geometry so should be properly parallel.

Geodore do a similar one as type 137 P with, apparently the same pivot arrangment. Looks to be a bit more expensive than the Stahlwille.

The one in the Cromwell link isn't parallel grip.

The general give-away for parallel action is three visible pivots arranged in a triangle. One on the handle, one on the jaw and one on the body. There is a forth pivot hidden inside that just peeks into view when fully open.

The ordinary, arcuate opening type only have two visible pivots. One on the handle and one on the body, both passing through the jaw forging.

Clive

That would be an expensive and elaborate toolmakers clamp. We have some of these hanging around for clamping sheets and blocks together for marking out and drilling. https://www.diy.com/departments/magnusson-20mm-spring-clamp/1782641_BQ.prd

I may well be incorrect, but I am pretty sure that none of the products linked to involve genuinely parallel jaw movement.

My original image A) does have genuinely parallel jaw movement because it has FOUR pivot points when are arranged parallel to each other in a rectangular/square design.

All the other product seem to have jaws in fact rotating around a pivot point. Although the impact may be subtle, at different degrees of jaw opening there amount of pressure on the part will be different at one end of the part compared to the other end of the part.

Either way, in order to minimise damage to the part I would like flat, not toothed jaws.
And I need it to clamp shut rather than lock in whatever position you got it to - if that makes any sense.

EDIT: Wait, the STAHLWILLE 65622250 seems to have a hidden fourth pivot point!

Here is the parallelogram

It's a clever design right enough! Although there seems to be an unnecessarily large number of layers of metal going on, so I wonder how strong it is in practice.

Either way I just don't like those teeth. But maybe one could get soft jaws for it. (Or yes, build if I have to!)

Edited By John Smith 47 on 05/05/2021 22:53:20

.

You might find this review video of interest: **LINK**

https://youtu.be/QEEcppQYqPs

MichaelG.

.

... and here’s a patent from 1945:

https://www.datamp.org//patents/displayPatent.php?pn=2388580&id=13778

... I wonder if anyone is still making that design 

Edited By Michael Gilligan on 05/05/2021 23:22:13

Btw, what do you think would happen if they fused Part A with Part B?

I've been trying to work it out... I think it would still work, no?

@MichaelG - yes, I found that video too.
Although it's painfully slow watching him winding it in and out.
It was always the one big problem with Mole grips all that winding!
You would need to be careful not to push on the thread as that will be rather uncomfortable in the hand.

One thing still puzzles me - why didn't they make the alignment of the parallelogram at 90 degrees to the jaws? The result is that it moves part with the lower jaw going forward in a slightly strange manner. Probably doesn't matter much but you would putting a slight shear into your part as you tighten it up!

What are you intending to hold, and what do you intend to do with the part once its held in your parallel hand clamp?

Without knowing what they're for it's hard to know what is suitable, when you're asking for very specific tools, you should give the very specific use so people can understand what you're trying to do.

These two pictures sound like what you are describing.

Also knipex pliers wrench close completely parallel, and the jaw force is magnified ten fold from how hard you squeeze the handles, they're like a hand held vice, I use them for squeezing things together.

.

... then I am surprised by your musings of 23:26:15

MichaelG.

There are very subtle distinctions in the mechanisms above. Some have parallel jaws; some have parallel action; one (the original photo) has, for want of a better term, perpendicular approach.

With parallel jaws, at any one point (i.e. when they are gripped onto the object), the jaws are parallel. As they move towards this point, the jaws may not move perpendicular to each other. All the ones above have this function.

With parallel action, the jaws stay parallel to each other while they are moving. The first one in the original post and the Stahlwille one have this function, as does anything with pivoting jaws.

With perpendicular approach, the jaws do not translate laterally as they close (so they are just like a vise). Only the first one does this.

Please consider the possibilities of these:

https://www.toolsntoolsuk.co.uk/shop/140-mm-side-screw-parallel-action-flat-nose-nylon-jaws-pliers-jewelry-extra-jaws/

The adjustment screw on them means that the distance between the ends of the handles can always be the same no matter what thickness they are gripping. You would have to make a locking device, but that can be as simple as a loop of metal, similar to that used by blacksmiths for a tong lock.

John

The Stahlwille and Geodore products have the same mechanism as may CK ones. The slight shear movement is an inevitable consequence of finite, relatively small, distances between the pivots. The shear is not an issue in practice because the actual movement between a firm touch when the jaws start to grip and clamp is small. The slight slack in the pivots needed for free movement also tends to compensate.

Fundamentally a bodgers tool. By the time mine come out I'm usually past caring about small marks on the job. Stilsons are the next step!

Assuming they are the same size as mine there are no strength issues. These things are significantly bigger and considerably heavier than the common Mole wrench. Maybe one and a half times as heavy as the equivalent size.

Clive

@Pete - It seems I wasn't clear enough. Like I say, the problem with all plier that have freely hinged jaw faces is that it is almost impossible to apply the same pressure to both end of the jaws at the same time. Indeed the ONLY way that you could achieve this would be to insert a part EXACTLY between the two hinges.

i.e. You have to locate a part at Position A.

For a small part this is horrible, because it is surrounded by over-hanging jaws.

i.e. If you locate a small part at Position B, the jaws just pivot and are no longer parallel.

The only possible option to hold a small part at the end of the jaws (e.g. imaging a small 1x1x1cm cube) where you can easily work on them, would be to insert and part of identical with at the opposite end (i.e. Position C).

@Clive - a parallelogram should be able to move things in parallel. The direction of movement depends on the chosen direction of the parallogram.

To my mind it is only a "bodger's tool" because of the teeth that will tend to mangle/bite into the part you are gripping. I don't care about weight.

@DK31 - Yes, but the "140 MM SIDE SCREW PARALLEL ACTION FLAT NOSE NYLON JAWS PLIERS JEWELRY EXTRA JAWS" are the same broad design as my original "Option A." i.e. Yes they have a nice parallel action, but they can't be made to grip like a vice.

On reflection, re my post at 05/05/2021 23:57:10, I see now that the core problem with the STAHLWILLE 65622250 (and it's cousins) is that one jaw is static. This means that as you open the jaws really wide that the jaw that moves will be going through some sort of arc (i.e. back towards the users hand).

* * *

OK to put my quest another way, I would like to have "a hand tool that is a fine-nosed vice - with a true parallel jaw action, and no irritating protrusion near the business end".

e.g. This attempt at a hand-held vice ("Precision Hand Vice Work Holder" tried hard to have parallel jaws (like a vice) but that sticking out head of the adjustment screw gets in the way of access pretty badly.

Probably not worth much more time thinking about this thread. Maybe what I seek hasn't been invented yet?

Edited By John Smith 47 on 06/05/2021 10:51:32

It does seem to be a common theme in your threads.

Try to make one

Yes, when I have time, I shall.

In the meantime, even though it's a potentially appalling time-sink, I find it interesting to see what is out there. It find fun and one learns a lot. 

But I have to say, basically rubbish tools do rather spoil the satisfaction of working in a small workshop and I have been doing a bit of a refresh of late.

Edited By John Smith 47 on 06/05/2021 11:51:57