What Are C-Clamps Used For?

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If your woodworking projects include tabletops or joints, gluing, or handsaw cutting, clamps come into play at some point. We love our power tools, of course, and hand tools often get forgotten. But clamps aren’t one of those forgotten hand tools.

In fact, you can’t have too many clamps in your shop, in a variety of kinds and shapes and uses. Virtually every project will require a clamp or two for something, whether holding a tabletop tightly or a joint,  while the glue dries.  Clamps come in a variety of types and sizes, so let’s start there.

Types of Clamps for Woodworking

We’ve written about clamps in past pieces, and you’ll find one of those articles here when we asked what types of clamps you need for woodworking. The list of clamps we discussed included:

And we provided a list of common clamps a beginner woodworker should stock in their shop.

For those tabletop and door projects, you’ll want to have a goodly number of pipe clamps as your first choice, and recommended a few 24” and 36” pieces of pipe with threads at both ends, along with the couplers needed to extend lengths for larger projects.

For smaller projects, bar clamps will come in handy, choosing a variety of sizes in the 12” – 24” range. These would be to supplement pipe clamps and will come in handy when the tabletop isn’t quite so large.

F-clamps can come in handy for smaller clamping needs, and a shop should have some to supplement the pipe and bar clamps. They start as small as 2”, but a variety of sizes in the 4” and 6” range, as well as a 12” and 24” size.

When it came to C-clamps, the final clamp on the list, we suggested just a couple for your clamp inventory. You’re likely to have some small pieces that will best be clamped with them.

Clamps are indispensable in an active woodworking shop. Virtually every project you undertake will call for their use at some point in the process. Today, we’ll focus on the c-clamps.

What Are C-Clamps?


C-clamps are so-called because they look like the letter “c.” The wide mouth of the “c” makes them very handy for some jobs that other clamps can’t handle or can’t handle as conveniently and easily. The tightening mechanism, though, can be time-consuming, as the wide mouth needs to be brought to bear on the pieces being held together.

To be honest, they do not do anything special or anything that any of the other clamps on the list can’t do just as well. The only exception is when a wider mouth is essential, and even then, not all the time.

The c-clamp was originally referred to as a “Carriage Clamp” that over time was shortened to simply the c-clamp. The “carriage” is in reference to using the clamp to carry sheet lumber – clamping the mouth tightly around the sheet and using the arch of the “c” as your handle.

The parts of the c-clamp include:

The arch also called the frame. This is the outer side of the “c,” and a cast iron frame can withstand a great deal of pressure on it and the workpiece when the clamp is closed.

The jaws. The gripping part of the clamp. One is stationary, and the other is moveable as the screw is turned to close it against the workpiece. This allows the jaws to hold different size workpieces.

The screw. The part you turn to close the moveable gripping plate to fit the workpiece. It uses an “ACME” threaded screw, which refers to a thread form with a 29-degree included angle for a stronger hold.

The handle. Self-explanatory and used to turn the screw both to tighten and to loosen.

Typically made of steel or cast iron, c-clamps are relatively inexpensive when new. We might suggest you check an online resource like Craigslist, though, as used c-clamps can be found for even less money. Their steel or cast iron construction makes them long-lasting and unlikely to warp, and bargains of already inexpensive models are common. We’ve seen them new, cast iron, for as little as $6 for a 3” clamp and sets of various sizes at $33 for a set of six 4” cast iron clamps.

Uses For C-Clamps

In woodworking, c-clamps are used to hold workpieces while they are being cut or drilled, in addition to holding glued pieces together while the glue dries. In metalworking, c-clamps are used to hold workpieces while they are welded or ground smooth.

C-clamps provide a very tight grip, and the grip plate can dig into a workpiece if the screw is turned too hard. It’s wise to always use a piece of scrap wood to protect the workpiece from damage by the plate. Beyond that precaution, the use of c-clamps is pretty straightforward.

We found a long list of other uses, though, that doesn’t necessarily have to do with either woodworking or metalwork. It came from one of our favorite and reliable sources, This Old House. Some of those uses include:

  • Bookends gripping a shelf on either end of a row of books
  • Carry large sheets of plywood, gripping the sheet and using the arch as a handle, living up to its original name, carriage clamp.
  • Critter defense by clamping the lids on rubbish barrels tightly to thwart raccoons and other varmints.

The list does go on, but you get the idea. C-clamps can be used in a number of ways outside the woodworking or metalwork shop, and all it takes is a little imagination.

Here’s a very basic c-clamp video that will walk you through its basic construction and use opportunities. It’s short, informative, and to the point.

Clamps are a necessity in woodworking shops, and we have a variety of types and sizes to accommodate most any need we have been able to anticipate. The pipe and bar clamps are the most often used, and every woodworking shop should have plenty of each in various sizes as a part of its non-power tool inventory.

Tabletops, desktops, and doors require clamp use while the glue is drying. Joints need strong clamping to allow the same from multiple directions.

There are some projects, though, where only a c-clamp will do. It’s true they can be an annoyance to tighten, as those of you who have used them know well. But when you need one, it’s good to have one handy.

They won’t break the bank, whether you purchase them new or used, and are less expensive than other types of clamps. You can never have too many, and eventually, you will develop your favorites depending on the types of projects you undertake. Those projects and uses will determine your future purchases, but again, you can never have too many clamps.

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