A clamp a tool with opposing, often adjustable sides or
parts for bracing objects or holding them together. It is an essential
fastening device to hold objects tightly together so that it can prevent
movement or separation while applying inward pressure. Clamps are a
versatile part of any tool kit. Clamps are used to secure a workpiece to
a work surface. They can easily secure a straight edge across a work
piece for routing and sawing. They can hold a workpiece during gluing.
Materials of construction of clamps include metals, plastics, and
Types of clamps
There are different clamps used for varied purposes. Some are temporary
while some others are permanent. The temporary clamps are those which
are used to position components while fixing them together. We give
below a list of some of the most common types of clamps:
What are the rules for clamping?
- C Clamp: C" clamps consist of a "C" shaped
frame into which an adjustable screw is assembled. The size of a "C"
clamp is measured by its capacity, which is measured by the
dimension of the largest object, the frame can accommodate with the
screw fully extended. Also important is depth of throat, the
distance from the center-line of the screw. to the inside edge of
the frame. "C" clamps range from 1" to 12".
- Bar Clamp: Bar clamps have a clamping device built on a
bar made usually of steel. Their length varies from 6" to 8".
The length of the bar
determines the capacity of the clamp, which is the dimension of the
largest object that can be accommodated between its clamping jaws. "Reach"
is the distance from the edge of the bar to the end of the clamping
jaws. Screw pressure applies the final clamping load. Another type
of bar clamp features one-handed operation. A pistol-grip handle
allows the woodworker to adjust jaw pressure with one hand where a
trigger release unlocks the grip. It is available in jaw openings
from 6" to 36". A pipe-clamp fixture is an adaptation of
the bar clamp. A set of clamp fixtures is mounted on a piece of pipe
of any length to make an economical, practical bar clamp. The
fixtures are easily switched from one piece of pipe to another.
- Spring clamp: A spring clamp is two metal jaws to which
clamping pressure is applied by use of a steel spring.
- Hand-screw clamp: A hand-screw clamp
two hardwood clamping jaws adjusted to the work by two steel screw
spindles assembled into the jaws. Also known as 'Toolmaker's
clamps', they are usually used in metalwork. They can also be used
to clamp small items. There are wooden hand screw clamps as well
which are used for furniture repairs.
- Web clamp: Web clamps
apply even clamping pressures around regular and irregular shapes
and hold tight by means of a spring-loaded locking fixture. They are
ideal for frames.
- Edging clamps: Edging clamps
are used for installing molding and trim on furniture, countertops
etc. They are also used for holding work at right angles, welding or
soldering. They are designed to hold edging strips, molding, trim,
etc., firmly when fastening to the edge or side of work, leaving
- Corner clamps: Corner clamps are designed to hold miter
or butt joints at a 90° angle. They can be used for making
picture frames, cabinets, molding and trim.
- Picture Frame Clamp: The clamp is so designed so that it
can hold the mitred corners of picture frames.
- Speed Clamp: This clamp is in the shape of a metal bar
with serrations. When there is application of clamping pressure, the
serrations lock & secure the sliding head.
- Screw Clamp: This type of clamp has a fast and powerful
closing and opening grip due to presence of special thread and
The steps to follow are as follows:
- It is very essential to use a piece of scrap wood between the
clamp's jaws and the workpiece so as to prevent damage.
- When a clamp is positioned, the jaws should be closed till the
clamp feels tight. In some cases when gluing, some will be squeezed
out around the joint, which implies that it is tight enough.
- It is to be noted that clamping pressure should be applied at
right angles to the glue line. If this is not done, there is chance
of slippage .
- Never over tighten a clamp. The purpose of a clamp is not to
force two surfaces to fit but to maintain uniform pressure between