Hi, can anyone recommend a good G clamp, there seems to be a lot of variation in price and so i assume quality. Im guessing drop forged would be less brittle than cast verities?

 

tnx

Andy

I like those:

They are strong and the thread will last forever compared to the fine thread others have

I generally dont use them, I find carver rack clamps much better

have lots of the 3 ton ones and fewer of the 5,7.5 and 10 ton ones, some straight bars you can use to clamp long items or reverse the heads to use as a spreader.

they are expensive though

Strange,   In the states that would be called a C clamp,  Not a G clamp.

not really strange when you consider many tools and associated names came about on their own, long before cross cultural exchange of information.

I tend to buy used at boot sales and jumbles (and sometimes at scrap yards).  They are on my "buy whenever a good one goes cheap" list as like pipe clamps you can never have enough!  (Worked in a custom woodshop once where we had a project that took all 100 of our pipe clamps *and* another hundred pipe clamps borrowed from another wood shop!)

 

Clamps marked China I only pick up off the side of the road free and tend to give them away or retire them in place in low stress jobs

 

With a large screw press I can even re-set sprung ones as long as the problem area is somewhere I can get the press to

From a machinist view, once you use some "Kant-Twist" clamps, all others seen a poor design.
Love them, and regular c - clamps rarely ever get used.

Maybe "Kant-Twist" clamps are good for machinests but they suck for fabrication as they simply dont generate any real force.   I use Bessey sliding F clamps, The heavy series ones I use generate 4 tons of clamping force.   the only C style clamps I use are heavy bridge clamps.       A 12" bridge clamp weighs 40 pounds and generates 20 tons of force.  (they also cost around $300 each)

Monster; I once ran into a small pile of the massive clamps at the scrapyard buried under a dumped load---had to pay US$15 apiece for them.  Never regretted it as I sold one and paid for the lot...

Couldn't be without my vice grip c clamps!

And Iron Dwarf I think you have some bad information.    Carver clamps are fantstic but they dont make any 10 ton rack clamps.    They are rated in daN.   The standard duty clamps produce about 2500 lbs of force and the big beefy heavy duty ones make about 6000 lbs of force.    The standard duty long reach ones are only good for 1250 pounds of squeeze.    The bar style clamps are even less.

 

That is one of the reasons I use the Besseys.     I like the Carver clamps but for the price the Besseys produce a lot more holding power.    The largest series of Besseys will produce 8500 pounds of squeeze, over a ton more than the Carver and they are less expensive.    For doing heavy work you need heavy clamps.    If your doing sheet metal or light duty work I suppose its unnessasary to have clamps that will pull together 3/4" plate when its got a 3/8" warp

 

I do wish the Carver clamps where a little more prevelent in the states.   I would like to have some of there part clamps and deep reach clamps but I worry about ordering them online.  I have bought clamps before that seemed like what I needed and then got them in my hand and they not been what I expected.   At a few hundred bucks a pop its hard to order them just to see.

 

 

MM- those Bessey F's are XXXX nice clamps!
I haven't used the Kant-Twist clamps with heavy vibration applications, so I can't comment on that.
But I really like them for machining and welding applications where nothing twists out of orientation when tightening, and the the self-aligning jaws are always parallel to what you're clamping in place. I'm sure you do a LOT larger scale stuff than I ever would, so I guess it is all in the application.

But I'm wondering about when you say the KT's don't generate any real clamping force. My catalog indicates a 12" capacity KT can make 6000 pounds of holding capacity.... you have to move up to the "Extra Heavy Duty" F-Clamps to get that much, and about 3x the price. A 10" KT is rated at 3500 pounds, still more than the Regular Duty F-clamps, and at a cheaper price. But I don't disagree that the F-clamps are very nice!

the large carvers I have are 2" by 1" rack, standard reach ones of this type last time I looked ( a long time ago ) were listed as 10 tons.
in that series I have straight bars up to 4 foot long and clamps 6 foot long, with the smallest series of clamps I have from them I can squash 2" box section about 3/16 thick to 1" by 3".

in the small clamps I have 6" and 12" long and several straight bars that take the same heads and can be clamps or spreaders, have a few long and medium reach heads and clamps,

they are great, will post some pictures when I get time


for machine clamps I use lenkes german made clamps on T slot tables.

IForgeIron Blueprints
Copyright 2002 - 2014 IFORGEIRON, All rights reserved

Clamps
by Glenn Conner



You have one heavy clamp but you have a project that needs two or more heavy clamps.

Your a blacksmith, make one.



All you need to do is to figure out what size stock you will need, then double the size. I figured that 1/2 inch square was about right so I used a piece of 1 inch square bar.

Just heat it up in the forge, make a couple of bends, and weld a nut on the end of the bar. A piece of all thread rod with a " T " welded on the end forms a handle to activate the screw. I figured that 1/2 inch all thread would work. If not, I can cut the weld and use heavier material for the screw.

Cost = zero, just using the materials in the resource center (scrap pile).

Hmm I would probably drift a hole near the end and tack the nut on the bottom of the hole so the force is up against the stock in use but the weld doesn't need to stand the force.  Drift the hole so max stock left on both sides.

Or tap the hole itself if the material will take the load without shearing the threads?

It was a quick and dirty clamp ot get the job done.. 

 

I like Thomas's idea of drifting a hole in the stock and welding the nut on the bottom side of the hole. Thanks

I picked up about 20 Armstrong C clamps 4" 6" 8" and 10" for 1 dollar a inch  a few years back, government surplus.  Our tax dollar hard at work.  xxxx fine C clamps.

 

Russell