“You can never have too many clamps” (credit: every woodworker who’s ever lived). Though outsiders might not get it, it’s such an oft repeated adage for a good reason: It’s true! But it’s not always about quantity. It’s just as important to have the right clamps for the job. Home Fixated sponsor Rockler sent us some of their new F-style piston clamps to put to the test. These beasts have several innovative features and incredible power! Let me show you why I’m so excited about Rockler piston clamps.
Rockler Piston Clamps – Passing The Bar Exam
The first thing I noticed about these new Rockler Piston Clamps are their impressive heft. I own and use a lot of clamps, especially when batching out projects. In a length for length comparison, these babies contain more gravity than the others in my collection. A lot of the mass is locked away in the cold rolled steel bar.
Every bar clamp I own exhibits some flex as you tighten the jaws. Granted, a little flex isn’t necessarily a bad thing (though it can be an issue in some cases, especially with longer bars). But a massive bar is a telling characteristic of a high quality clamp and the bar on these piston clamps puts most others to shame! Even when I tightened the longest clamp as much as I could – with the jaws wide open – flex was negligible.
Great Throat Depth with Slip-Resistant Teeth
Rockler piston clamps have a 4-3/4” reach, letting you apply pressure farther from the edge of your workpiece, as needed. Most clamps have fairly shallow throats – especially those with flimsy bars – partially to mitigate the flex that occurs as you apply pressure. I’m happy to report that’s not a problem here.
Another thing I like are the teeth that grip the bar. Many bar clamps use a stack of spring loaded steel plates (or worse, nothing but leverage) to provide the bite that holds the jaw in place as you tighten the handle. That generally works well, but the plates can sometimes be tough to release after a clamping that really caused them to dig into the bar.
Rockler piston clamps have teeth in the dynamic mandible (the jaw that moves). Simply tilt the jaw and it’s free to slide along the bar. Granted, many cheapie bar clamps also use a free sliding jaw. But their jaws almost never have teeth; not even dentures. Not only do the teeth do a fantastic job of biting once the clamp is cinched but, they also excel at preventing the jaw from slipping while you’re trying to establish that initial grip, which is a genuine hassle with a lot of lesser clamps I’ve dealt with.
As far as I can tell, the teeth are milled from a separate piece of hardened steel and should stave off tooth decay for a lifetime.
Putting The Piston In Rockler Piston Clamps
The swiveling pads of most screw handle F clamps suffer from an annoying tendency to twist and misalign your workpieces, sometimes making a simple glue-up more tedious than necessary. The piston in Rockler’s piston clamps – and other piston clamps made by Piher (the same company who manufactures them for Rockler) – advances without rotating, completely eliminating the twisting problem.
The pistons on the Rockler Piston Clamps conceal an interesting little secret: a double threaded bit of genius that advances the piston at a faster rate than turning the handle otherwise would. In other words it takes less rotations of the handle to get the job done.
Handle The Pressure With Rockler Piston Clamps
That pretty blue handle is made of a very tough, durable plastic. You’d think its girth and hexagonal shape would give you an excellent grip and allow you to really torque it down. But you’d be wrong. In fact, the texture of the plastic actually makes it somewhat slippery, almost like nylon. Not the best material for getting a firm grip. See the test results later in this article for more on this.
I mentioned the somewhat underwhelming handle traction. But don’t let that discourage you. These babies have another trick up their sleeve: the handle folds over at 90° – acting as a lever and giving you way more torque than just about any comparable clamp on the market – for clamping pressures up to 2,000 pounds, according to Rockler!
Lest you think the plastic handles aren’t up to the task, I put one in the right angle position and tightened it as hard as I could (under the weight of my rotund upper body) and the handle showed no sign of deflection.
Another nice touch is a hidden spring that firmly holds the handle in whichever position you place it by pulling the pivot rod into detents on the end of the handle.
Padding The Budget
For best performance, I highly recommend getting the custom clamp pads when buying Rockler piston clamps. The pads help distribute the pressure over a slightly wider area to reduce marring, especially on soft materials like pine and cedar.
The clamp pads have locking tabs to keep them in place. They’re even hard to purposely remove. This is a huge upgrade from the pads that come with most F-clamps, which readily fall off and get lost if you so much as look at them funny. For $2.99, I consider them a must-have add-on.
Rockler Piston Clamps – It’s Crunch Time
If the proof of the pudding is in the tasting (that’s the proper way to state the expression, by the way), then the proof of the clamp is in the crushing. The best way to judge relative clamping pressure is to crush the hell out of some wood. So I grabbed a piece of pine and proceeded to mock it, insult it with “your mamma” jokes and crush the very fiber of its being. And I didn’t even apologize.
As a control, I pit its clamping power against the most comparable clamp I have at my disposal: the mack daddy orange Jorgensen that Home Depot used to carry before they switched to the noticeably wimpier (but still pretty decent) Irwins they have now.
My first test was with the piston clamp’s handle in the straight position. Frankly, I found to hard to really torque it down. The resulting clamping pressure was acceptable, but not as mighty as that of the Jorgensen. But wait; it gets better!
One Hulking Clamp
Toggling the handle to 90°, however, is the clamping equivalent of pissing off Dr. Bruce Banner. Only in this case, you will like him when he’s angry. The increased leverage makes it easy to torque the hell out of it. For test purposes, I used all my might to tighten the clamp way more than you’ll likely ever need in any real life scenario. And let me tell you, that wood was begging for mercy way before I hit peak force. Other clamps? They’ll be turning green – with envy.
My Latest Crush
If you aren’t yet convinced of the fury embodied within the piston clamp, feast your eyes upon the test plate pictured above. All four indentations were made by tightening the clamps with the full strength of my unaided 2-handed grip. In tests 3 and 4, I was able to put my upper body into it for even more torque.
#1: Jorgensen clamp with no pad.
#2: Rockler piston clamp with no pad and the handle in the straight position.
#3: Rockler piston clamp with no pad and the handle in the 90° position.
#4: Rockler piston clamp with pad installed and the handle in the 90° position.
As you can see, the piston clamp’s available pressure is rather substantial! In general, it’s considered good practice to use a piece of waste wood between your clamps and your workpiece to prevent accidental dents and crushing when applying higher clamping forces. But this test was all about the damage.
Real Life Application
There’s no denying the incredible crushing power of the piston clamp. But clamping isn’t necessarily about brute force. In most cases, a much more ginger approach is in order. It’s doesn’t take 2,000 pounds of clamping force to glue a couple of boards together or assemble a night stand. You may not even need to cock the handle for most woodworking tasks, but the power is there when you need it.
I was given this broken 1-1/2” thick (“6/4”, for those in the know) cedar board a while back. I figured this would be a good time to repair it. A little glue and moderate clamping pressure was all it took restore it to perfectly usable condition, great for carving or some other project.
The waxed paper you see in the pictures is there to protect my clamps and work surface from dripping glue. It also prevents the wood from being glued to the table. Waxed paper is dirt cheap; it’s a good idea to keep a roll or two in the shop for use during glue-ups
Making The Grade
The above photo compares some of the screw tightening F-style bar clamps commonly available from big box retailers. From top to bottom: Harbor Freight, Jorgensen, Rockler piston clamp, unbranded (though I seem to remember buying a bunch of these years ago in Bessey branded discount multi-packs), and a branded Bessey. The closest match – in my collection – is the orange Jorgensen.
When weighing performance vs. price (the price point is on par with clamps of similar quality on the market and actually cheaper than piston clamps sold under Piher’s own brand name), the Rockler piston clamp goes right to the head of the class. This is one F clamp that’s truly earned an A+.
You can buy the Rockler Piston Clamps here:
And the clamp pads are here: