7 FEBRUARY 1987, Page 26

Sir: I can provide one meaning of `pilger- ing'. Pilgering

is the operation performed by a Pilger Mill and is a method of producing steel tubes presumably named after the inventor. It is a process employing a pair of eccentric rollers rotating contrary to the feed of the material — a forging action producing a lot of noise and stress in the machinery.

David Clarke Northern editor, Industrial Equipment News,

Hall Ing House, Honley, Huddersfield, Yorkshire