In 1961, a blacksmith from Sheffield, John Brailsford, then a teacher of engineering technology, created the ever first purpose designed nut, the Acorn. Three sizes (1 inch, ¾ inch and 5/8 inch) were turned on a lathe from extruded aluminium alloy. John Brailsford also tried Tufnol (a resin bonded fibre used by Rolls Royce or Hoover for making light weight, silent gears) and brass for their different properties of hardness. Since the Acorn had a machine nut sitting on its top and threaded on the same sling, this « nest of nuts » offered two options, the machine nut or the Acorn. They were probably the first nuts to be marketed in England, by the Roger Turner Mountain Shop in Nottingham.

Most of the difficult cracks which were climbed by hand-jam and layback techniques needed however a wider nut. After measuring some of them, John Brailsford, always him, made models in balsa wood in the form of truncated, oblong pyramids. A Derby company, Coronet Tools, specialising in aluminium casting made six prototypes in L.M. 6 in which John Brailsford drilled two holes and created a radius to join these holes.