Last edited 09 Feb 2020

Clamp and cramp

A simple cast iron G-cramp (or C-cramp).

1 Introduction
2 G- or C-Cramp
3 Sash cramps
4 Vehicle (or car) clamp
5 Related articles on Designing Buildings Wiki

[edit] Introduction

A ‘clamp’ (sometimes called a ‘cramp’) is a tool (often made of cast metal) which applies a force to hold two or more objects tightly together. This may be for a temporary period after which the parts will be separated, or they will hold together without the aid of the clamp (for example if they have been glued or screwed).

The word ‘clamp’ tends to be used in engineering while ‘cramp’ tends to be used in woodworking, although to a large extent, the two terms are interchangeable.

In woodworking, a cramp may be used to hold two or more pieces of wood together for as long as it takes for an adhesive to set. Cramps can also be used to hold together assemblies temporarily (before any adhesive is applied) to see how they will fit together. They can also be used to hold small assemblies together while they are being worked on.

[edit] G- or C-Cramp

Formed in the shape of a ‘G’ (sometimes referred to as a ‘C’) these metal cramps have a screw mechanism that can be adjusted until the items in question are held tightly. The screw is turned until the object is gripped tightly between the cramp’s adjustable shoe and the cast-metal frame.

[edit] Sash cramps

These are used to clamp together large frames, for example, window frames or drawers. They comprise long metal bars with a screw-adjustable grip at one end; the other end comprises a free-moving jaw that can be adjusted to points at predetermined intervals, usually by inserting pegs into pre-drilled holes. Once the object is in position and the peg inserted into the most suitable hole, the screw end can be adjusted to grip the item firmly.

[edit] Vehicle (or car) clamp

In another application, a clamp is attached to one wheel of a vehicle in order to immobilise it, for example, until a fine is paid to the satisfaction of a parking authority. In this case, the clamp is to prevent mobility rather than to force two objects together.