Henry Maudslay - Screw Cutting Lathe

Screw Cutting Lathe

At the time when Maudslay began working for Bramah, the typical lathe was worked by a treadle and the workman held the cutting tool against the work. This did not allow for precision, especially in cutting iron. Maudslay designed a tool holder into which the cutting tool would be clamped, and which would slide on accurately planed surfaces to allow the cutting tool to move in either direction. The slide rest was positioned by a leadscrew to which power was transmitted through a pair of changeable gears so that it traveled in proportion to the turning of the work. This allowed screw threads to be precisely cut. Changing the gears gave various pitches. The ability of Maudslay’s slide-rest lathe to produce precision parts revolutionised the production of machine components.

A misunderstanding persisted for many years that James Nasmyth had claimed that Maudslay was the original inventor of the slide rest. By the mid-20th century informed historians understood that Maudslay was not the first person ever to build a slide rest, or to use one on a lathe. But he was in fact the person who combined the slide rest, leadscrew, and change gears in a precision machine, which popularized the concept and caused modern industry to widely adopt it.

Maudslay's original screw-cutting lathe is at the Science Museum in London.