JackClamp Clamping System - Canadian Woodworking Magazine

A versatile multi-functional tool with the ability to clamp, spread, jack, and hoist.


JackClamp Clamping System

Bar and pipe clamps are great for clamping panels, cabinet carcasses, and the like. Because they typically have thick beams they flex very little, and they often have large clamping jaws that provide a more even distribution of clamping pressure. But what most woodworkers really like about them is the tremendous pressure they exert – upwards of 1,500 pounds of clamping force.
However, for a lot of gluing jobs you really don't need all that clamping power. When applying edge banding, gluing up face frames, or assembling mortise and tenon joints or drawer parts, a clamping pressure of 250 to 300 pounds per square inch will do the job.

Among the most versatile of general purpose clamps are those commonly referred to as 'quick-grip', 'ratcheting', 'one-handed', and 'clamp/spreader' clamps. While the JackClamp looks somewhat like a conventional clamp/spreader, it has some unique features. The JackClamp is available in a kit, which includes two Jack Clamps, two spreader attachments, two V-jaw attachments, and two feet attachments. You can also purchase single units.

The JackClamp functions as a clamp, spreader, hoist, and a jack. The extra functionality is due to the additional top bar mounted above the main clamping bar. The bars are made of 1/4" by 3/4" steel, and won't flex at all under load. The jaws are made of glass-filled nylon, which increases their impact and structural strength, and makes them very rigid. The jaw pads are 1-3/8" by 1-3/4", somewhat on the small side, compared to other similar clamps that I've used.

JackClamp in clamping mode

In most woodworking shops I think that a 'clamp/spreader' style of clamp is generally used in the 'clamping' configuration.You can use the JackClamp in the clamping mode with either the top bar installed or removed. With the top bar installed, you get an 11-3/8" clamping capacity. Removing the top bar takes all of 5 seconds, so its best to remove it for most clamping operations – this will also give you a 13-1/2" clamping capacity. The throat is 2-1/8" (measured from the center of the pad to the top of the main bar). 
JackClamp in spreader mode

Switching to the spreader mode takes about 10 seconds. You just remove the main bar and reinsert it into the back of the handle. In spreader mode you get a maximum spread of 33" and a minimum spread of 8". With 300 pounds of pressure it can disassembly just about anything. 

JackClamp in jack mode

I rarely used clamps for spreading, but the idea of a clamp that can be used to jack up cabinets intrigued me. To use the JackClamp as a cabinet lift configure it as you would use it in the spreader mode. Then install the two feet that come with the kit onto the back of the main bar. Once installed they provide a stable base for the clamps to be positioned vertically. It's then just a matter of squeezing the handles to jack the cabinets into place. The JackClamp has a jacking capacity of 19" to 34", and a 300 pound weight limit. If you install kitchen cabinets, then this is a great tool for setting the upper cabinets after the base cabinets are installed. However, you have to install the upper cabinets before you install the countertop, as kitchen cabinets are usually installed about 18" above the countertop (see the photo above).

JackClamp with spreader attachments (photo courtesy of JackClamp)

The JackClamp kit also comes with a pair of spreader attachments that you can use when installing decking or flooring. The spreaders make it easier to force boards into position. You get a spread capacity of 1/4" to 11-1/4".

JackClamp with V-jaw attachments (photo courtesy of JackClamp)

The V-jaw attachments take the hassle out of securely holding round stock. You can use them with plastic or metal piping as well as with wood dowels.Installing the feet on the JackClamp enables you to create an upright clamping system (see the photo above)


The JackClamp is one of the most versatile multi-functional clamps on the market – in fact, I doubt if there is anything else quite like it. I think that the ability to clamp, spread, jack, and hoist with a single tool will make the JackClamp of interest to DIYers, renovators, cabinet installers, service technicians, and other tradespeople. If you just need is a pair of clamps, then you can purchase the JackClamp separately. The only issue I can see is that a single JackClamp sells for about 60% more than an Irwin Quick-Grip clamp of the same clamping capacity. However, if you only need a couple of clamps, then the extra cost can easily be justified by the increased utility of the JackClamp.


  • 1/4" x 3/4" steel bars
  • 1-3/8" x 1-3/4" removable clamping pads
  • 2-1/8" throat (middle of pad to bar)
  • Clamp up to 13-1/2"
  • Spread up to 33"
  • Spread gaps with optional spreader attachments: 1/4" to 11-1/4"
  • Jack or hoist up to 300 pounds
  • V-jaw attachments for round stock
  • Built-in level
  • Lifetime guarantee
  • Kit Includes: 2 Jack Clamps, 2 spreader attachments, 2 V-jaw attachments, 2 feet attachments

COMPANY:Lowell Thomas Tool Co.
PRICE:$119.99 kit; $54.99 single clamp
SOURCE:Lowell Thomas Tool Co.
July 2014

Carl Duguay
Discover more great woodworking reviews!
Subscribe Now and get instance online access to our library filled with exciting woodworking information.
Continue to stay connected to the latest tool reviews with our bi-monthly woodworking magazines!