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Bessey K Body® Revo™ Parallel Clamps
Stepping up the standard
Text, photos & video by Tom Hintz
Posted - 11-14-2008
Woodworkers have lusted after Bessey clamps for years. Now, Bessey revamped their parallel jaw clamp efforts evidenced by their new K Body Revo Clamps. Some of the changes are clearly visible, some not so much. But when you get them on the bench clamping stuff together, it all becomes very clear.
Probably the most obvious change is the new large diameter composite handles on the Bessey K Body Revo Clamps. A new larger diameter and soft plastic inserts make getting a secure grip on these handles much easier. This one change has been a very popular topic amongst Bessey users on woodworking forums and their wishes have been answered! The Bessey K Body Revo Clamp slip-free handles are more comfortable and the enhanced slip-resistant grip makes applying pressure easier.
Another visible difference is the addition of removable pressure caps on the jaws. These covers are resistant to glues, paints and solvents. Because they just slip on and off, when the inevitable spots of glue appear it is easy to flex the pressure cap and in most cases just peel the glue off.
They also added rail protection pieces to the Bessey K Body Revo Clamps. These clip-on pieces (two included with each clamp) can be located anywhere between the jaws to hold the pieces being glued off of the rail. These little clips will help eliminate those annoying spots of u-shaped glue where joints intersect the clamp rails. The rail protection pieces slip on and off of the rail and have holes in their lower arms that allow using the Bessey TK6 table clamps to secure the Bessey K Body Revo Clamps to the work surface.
Not So Visible
Bessey literature says the Bessey K Body Revo Clamps sport 30-percent more clamping surface than their previous versions and 25-percent more clamping force. Bessey also claims that the internal structure of their Bessey K Body Revo Clamp jaws insure accurate 90-degree angles to the rail, even under maximum pressures. I certainly cannot find anything to refute that!
The Bessey K Body Revo Clamps moveable and fixed jaws (pressure caps in place) are 3-3/4"-tall above the rail and 5-3/4"-tall overall. Both jaws are 2"-wide. Without the pressure caps the jaw surface shrinks slightly to 3-1/2"-tall (above the rail), 5-5/8"-tall overall and 1-3/4"-wide. However, I can see no benefit to removing the pressure caps.
Of course, the tough, rigid all steel rail remains. This 5/16"-thick by 1-1/8"-tall rail has a gentle hourglass shape and a continuous row of precisely formed ridges along the top and bottom edges. It is these ridges and the mechanism within the moveable jaw that give the Bessey K Body Revo Clamps their ability to resist the tremendous clamping forces generated.
Though there are no obvious clues, Bessey has stepped up the clamping power on the K Body Revo Clamps. The cleanly formed Acme-style thread on the handles and the internal parts that it operates are at least partially responsible. Whatever they did, the clamping force is more than adequate for any mortal woodworking job I can think of. As before, this mechanism works smoothly and applies the necessary force without making you wish you had been working out more.
The moveable clamping head on the Bessey K Body Revo Clamps locks automatically when sliding away from the fixed jaw. When sliding towards the fixed jaw, the moveable jaw slides freely. Lifting the handle slightly frees the moveable jaw for opening.
Push Me, Pull You
The moveable jaw on the Bessey K Body Revo Clamps can be slipped off of the end of the rail and reversed for spreading operations. Years ago I thought this was a useless feature but have since learned through experience how handy this capability can be. Actually reversing the moveable jaw on some parallel clamps could be a real chore, especially getting the locking plates within them to align so the rail would pass through. The Bessey K Body Revo Clamps suffers no such problem. The moveable jaw can easily be slide off, reversed and then back onto the rail for spreading tasks. Because the handle is also reversed, the minimum opening the Bessey K Body Revo Clamps in spreading mode can accommodate is about 10".
Because the internal locking mechanism and the ridges on the rail are non directional, the Bessey K Body Revo Clamps develop the same levels of force in the spreading mode. We seldom need to use that much force when spreading pieces in a project but it is nice to know the Bessey K Body Revo Clamps area capable if we really get ourselves in a tough spot.
In the Shop
While using good parallel jaw clamps has never been tough, the quality of the Bessey K Body Revo Clamps makes it easier. The squareness of the jaws and the smooth application of clamping pressure make assembling projects correctly a simple task. The ease with which the moveable jaw can be repositioned is also helpful as is the tail piece that keeps the Bessey K Body Revo Clamps level on the work surface and allows repositioning the movable jaw without sliding the clamps and wood around the table.
The tremendous clamping power the Bessey K Body Revo Clamps are capable of producing and the ease with which it can be applied with the new grip style can work for and against you. Some woodworkers are obsessed with huge clamping pressures even though applying that much force all but guarantees starving a joint for glue. For those who understand this, (and want strong joints) using the Bessey K Body Revo Clamps is virtually effortless. Applying the necessary amount of pressure to seat a joint takes very little effort. Of course if you just feel better trying to crush the wood and are not worried about joint strength, feel free to crank away. I suspect that the Bessey K Body Revo Clamps can probably handle more pressure than is reasonable also.
I did try to apply enough pressure to skew the clamping jaws. Though I tightened the Bessey K Body Revo Clamps with all of the force I could generate by hand, the jaws remained square to the rail, and each other.
The Bessey K Body Revo Clamps live up to the legendary Bessey reputation, and then some. These are tough, easy to use and very accurate (square) clamps that will make assembling projects easier. Because the Bessey K Body Revo Clamps are built using high-end materials and manufacturing, they will remain a useful part of your woodworking shop for many years. With a street price of between $34.99 for the 12" version and $54.99 (11-13-2008) for the 60" ones, building a selection of Bessey K Body Revo Clamps can - with a little restraint - be done without a government bailout.
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