POWERTEC20326 Quick-Release Horizontal Toggle Clam 225D - 500 lb Holding Capacity w Rubber Pressure Tip, 4PK

Bought several of these, they work well. Adjustment of the main pin can be a bit fiddly but once adjusted they are fine and it's not hard to do anyway.

Horizontal toggle-clampPosted 5-30-15(Note this is the “Horizontal” reference, I replaced the review I did for the Horizontals with this one.)Great Clamp. In some machine shops, we called these "Grasshopper-clamps". In other shops, I've heard them called "spring-clamps" "toggle-clamps" or "toe- clamps". They come in all sizes but the general shape of the clamp is the same. They're a fast way to quickly secure your work-piece for production runs or repetitive operations.The "Horizontal" clamps such as these lock in and apply pressure to the work piece when the clamp's lever is pressed down. This makes the clamp have a low profile and the better choice for most vertical milling and drilling operations.However, on rare occasions I may need the vertical action clamp and therefore ordered a pair for some future project. Be careful to note which version you're ordering! In fact, I’ve written and posted a review for the Vertical configuration as well.It’s IMPORTANT to remember that these clamp levers are not a “variable position” lever. THEY MUST “LOCK-DOWN”, ( all the way down to the horizontal position), in order to hold down the work-piece!The “vertical action lever” clamp configuration must “lock-up” in the vertical position.There are no ‘in-betweens’ and if either style, (Horizontal or Vertical), are not in their locked position, you’re in danger of ‘throwing’ the work piece and being hit by it. You adjust for the thickness of the work piece by increasing/decreasing the toe-screw. If the work piece e is thicker than the clamp can adjust for, make an appropriate size ‘base-block’ to shim-up the clamp.The clamps come with an adjustable toe and the hardware is of decent quality. The threaded stud and retainers look to be ¼-20 and about 2.” long. These clamps have 4 holes, (about 7/32 in diameter), for screwing it down to a jig design or work-surface. If you don't want to drill into your machine's table surface, you'd use the 4 holes to screw it down to a home-made/designed "adapter base" for a T-Slot anchor method, (my preferred method).These clamps are strong enough to exert at least 50-100lbs down on the work piece and if you want to make it a bit ‘beefier’, you can easily replace the ¼-20 hardware with your own 5/16-18 or 5/16-24 hardware. The contact tip is a ‘molded-on’ rubber material, which is good for a number of applications.However, if the job you’re doing will cause the rubber to melt or react in some negative way, you’ll have to replace it with a ¼-20 or 5/16-18 stud. Again, the more expensive, commercial grade clamps often have contact tips that can be removed from the adjustable stud.I don’t think I would count on the clamp to exert 300lbs on the work piece with these clamps, which is their advertised rating. In fact, I know I wouldn’t use these for any large drilling or cutting-tool operations. I’d stick with light duty applications.Remember, the rating of this clamp regards the “Down-Force”, but the tool pressure and side force of a twist drill is among the highest of most machine cutting tools! The side/twist forces of a ½ drill in an annealed, carbon base steel, (or even other materials that you would never suspect), can be generated well above 100lbs.My point is that these forces would easily overcome the clamp’s ability to hold it and slide the work piece out from under the clamp if the piece isn’t against a rigid stop. The down-feed pressure of the drill will not overcome the twist cutting forces.A rather short, 20 or 30lb chunk of steel may seem heavy enough to stay still on the drill/mill table while drilling a 3/8+ hole in it, but if it’s not clamped down and against a rigid stop, it’s almost guaranteed to get thrown, (and that’s the least that could happen).The clamps are worth the money and you do get a good bang for the buck. As I said earlier, the 300lb rating is something I wouldn’t count on. How well this clamp can secure the work-piece is very much dependent on a number of other variables.The operation you plan to perform and the kind of material you’re working with are just a few, (and let’s not forget the specs/ratings of the fasteners you use to anchor the clamp itself). Of course, the most important one is ALWAYS how well you set the job up before you start!I would definitely buy these again if/when I ever need them, 5 Stars!Rich(Just an “FWIW”)The largest “Grasshopper-Clamp” I’ve ever worked with, weighed almost 40lbs, (I’ve seen bigger ones than that, though!). They were used for ‘quick in/out’ production jobs that didn’t require holding an extremely close tolerance and didn’t involve a high amount of “horizontal” cutting-tool pressure.Even when the work piece was a stainless steel plate at least 48” x 48” x 4” in size, we would use 4 of those clamps. Each clamp could easily have exerted a 1000-psi on the work piece but I wouldn’t use them for anything but small hole drilling operations.Typically, on a medium to large Radial Arm drilling machine, a 2” diameter drill would be considered a “small hole”, (it’s all relative, isn’t it ;). Those industrial, commercial-grade clamps pretty much looked like these little ones but with a higher quality hardware and adjustable mechanism.

Conforme à mes attentes

Used on a homemade router jig.

Not to small, not to big, just the right size for my drill press table / fence gig. Hold down strength more than enough.