The "3HG" and "4HG" were the largest of the Adcock and Shipley conventional horizontal millers. The "3HG" had a swivelling table 60" x 14" with a longitudinal travel of 36" and a transverse travel of 12"; the knee could be elevated through a distance of 19". A 15 hp motor provided speeds from 23 to 1250 rpm.
The "4HG" was even more massive, and although the knee moved through only an extra 1/2" of movement the massive 72" x 17" swivelling table had 44" of longitudinal and 15" of transverse travel. A 25 hp motor ensured that the biggest jobs could be handled quickly by impatient but skilled machinists - the aim being to take a substantial cutter and make it remove as much metal in one pass as possible - in other words, take the machine almost to the stalling point and then back off whilst the cutter buried itself in the work and the chippings piled up around the job faster than they could be removed.