People often use cramp and clamp interchangeably, for example, referring to a sash clamp as a sash cramp. This got me wondering, is there actually a difference?

Short answer

Clamp and cramp generally mean the same thing and are often used interchangeable.

A cramp is a tool that temporarily holds objects together. A clamp can refer to a tool that temporary or permanently hold objects together. This means that all cramps can be called clamps, but only non-permanent clamps could be called cramps.

Long answer

Based on older (and some modern) texts, the difference between clamp and cramp is that cramps are tools which temporarily hold items together where as clamping means to permanently hold objects in place ^{1 2 3}. However, there are also older texts that contradict this by swapping the meanings ⁴ or using the terms interchangeably ⁵.

What about modern usage? Wikipedia states:

In the United Kingdom the term cramp is often used instead when the tool is for temporary use for positioning components during construction and woodworking; thus a G cramp or a sash clamp but a wheel clamp or a surgical clamp.

Wikipedia – Clamp (tool)

which appears to match some older texts although, at least with some texts, the same was also true of US English, not just UK English.

After reviewing multiple sources, it appears that there is no consensus on when to use the term clamp versus cramp in modern usage. What can be said is that cramp is less common in modern US English compared to UK English. However, in both countries, clamp is now the most common term used.

It’s probably safe to say, if there ever was a clear distinction, it has now largely been lost and the terms can be used interchangeably when referring to tools used for temporarily holding objects together.

References

1. Cassell’s (1908) “Carpentry and Joinery” ↩︎
2. Robert Wearing (2010) “The Essential Woodworker” ↩︎
3. Joseph Moxon (1683) “Mechanick exercises, or, The doctrine of handy-works” ↩︎
4. (1879) “Carpentry and Building” Volumes 1–3 ↩︎
5. E. & F.N. Spon (1886) “Spons’ Mechanics’ Own Book A Manual for Handicraftsmen and Amateurs” ↩︎