Introduced in 1937 the Allis-Chalmers Model B continued in production until 1957 during which time over 125,000 were sold.  It proved to be one of the best all-round tractors in the 20 hp range for many years.  The original 13/16 hp four cylinder engine was enlarged in 1944.  Despite the relatively light-weight appearance the 1,500 lb draw-bar pull equalled and in fact exceeded that of many of it's more substantial looking competitors.

The Allis-Chalmers Model B was the first tractor in the World to be sold fitted with pneumatic tyres without the option of steel wheels.  From 1947 the B was produced in the United Kingdom.  Initially assembled at the Totton plant near Southampton from components imported from the U.S.A.  Subsequently from locally sourced parts until in it's final form it was totally UK built at Essendine Leicestershire.  Supply companies includes Bean Industries for castings, Rubery Owen for sheet metal and ENV or Moss for transmissions etc.  A Perkins P3 diesel option, four speed transmission and hydraulics were distinct improvements but by 1955 the Ferguson TE 20 had set the standard and the Model B was no longer competitive, production ceased and it was replaced by the D 270.