Corner clamps are one of the handiest tools a woodworker could ever have. Whenever you’re making furniture or fixtures, a corner clamp will allow you to make perfect 90° connections between boards every time. With the right set, the corner clamps can be used to hold any board of virtually any size in place and keep them that way during the entire gluing and/or screwing process.
Because corner clamps are so versatile and so sought out, there’s an infinite number of clamps available. Although the wide selection of corner clamps makes it easier to find a pair in any hardware store or online shop, this also makes shopping for a high-quality, ultra-reliable, perfect-90° corner clamp a bit more than confusing.
We’ve filtered through hundreds of different models to find Mr. Right-Angle Corner Clamp for you. Any of these could be of tremendous help in your next woodworking project.
Ultimate Corner Clamp Buying Guide
We mentioned earlier in the article that the most reliable corner clamps can be difficult to find. For the most part, it is, but as long as you know what to look for in a set of corner clamps, you won’t have to have to spend hours researching every model you come across. In this guide, we’ll go over what key features a good corner clamp should have.
Holding large boards in place can take a toll on a corner clamp. The material used to make the unit should be able to withstand punishment for several minutes while you’re connecting boards. Most corner clamps are made of cast aluminum, which is quite durable and lightweight. But pay attention to the thickness of the clamp – too thin and it might snap under pressure. However, if you want the best of the best materials, opt for a heat-treated steel clamp instead.
Board Thickness Capacity
Not every corner clamp is made to clamp boards of the same size. Some are designed for light-duty tasks like making picture frames while others can hold onto boards as thick 2 or 3 inches. However, there’s no model that fits all needs; you may need to purchase different sized clamps for different projects.
Believe it or not, the color of the corner clamp has some importance in how reliable the tool is. It may be able to hold boards in place without the slightest budge or wiggle, but if clamped too tightly, it may end up leaving marks on your stock. You most likely won’t use corner clamps after adding finishing touches to the wood (paint, varnish, oil, etc.) so a little paint is nothing to cry over.
The greatest challenge amateur woodworkers have when building furniture or fixtures is getting the boards to stay perfectly squared with each other. Some corner clamps can help eliminate the guesswork with built-in self-squaring systems. This is especially beneficial holding boards of unequal thicknesses together to produce a perfect right-angle connection.
A “Third” Hand
No matter how careful you are, the slightest nudge may cause the clamp to release its gripping power on one side of the board, resulting in a skewed corner which saddens everyone in the woodworking world. You could always get a second pair of hands to help hold the pieces in shape before tightening the clamps, or you could find a corner clamp with a third hand that’s located in the inner part of the corner. The third handle carefully aligns and keeps the pieces in place while you twist the clamp.
The versatility of a corner clamp is judged by how many things you can get done while the clamp’s grips are in place. The most versatile models we’ve found have pocket-hole cutouts which allow the clamp to hold boards together while also allowing users to drive pocket screws. This is a nice feature but not a must-have by any means.
One often overlooked aspect of a corner clamp is the handle – the part that you twist to push the board against the clamp’s walls. The handle should be made of a durable material. Ideally the same used to make the actual clamp. Plastic is fine for smaller clamps, but twisting or gripping the plastic too hard can cause it to crack in your palm. However, if you’re careful, even plastic handles made in China can last for several years of regular use.
Corner Clamp FAQs
Although corner clamps are straightforward tools, it takes practice and time to get the hang of. Next, we’ll address some of the most commonly asked about corner clamps.
Do the connected boards have to be the same thickness?
Ideally, yes. Not many corner clamps are made with self-adjusting technology that makes working with boards of unequal thicknesses a breeze. However, you can use create a makeshift shim with scrap wood to compensate for the difference in thickness.
Can I use woodworking corner clamps for welding?
The benefit of welding clamps is the magnets that keep metal pieces together at the right angle. That’s not to say that woodworking clamps won’t work for welding, but at best, they should be used for tack welding and nothing more extreme.
How many clamps do I need?
If you’re building furniture, cabinets, or boxes with four corners, four clamps for each corner would be best. However, this isn’t necessary; you can always work one corner at a time with a single clamp.
Corner clamps are not a must-have tool for hardcore woodworking projects, but they do make fastening boards at perfectly right angles quick and easy to do. Corner clamps will come in handy when working with difficult-to-hold boards of super-thin or super-thick boards of up to 2 inches.
In this guide, we not only provide you with our picks of the best corner clamps, but we also show you how to find the best model available to you. There are several features that make corners clamps extremely convenient to set up, and some are versatile enough to allow drilling pocket holes while holding boards in place.