Mk. 4 Dial Type High-Power version. Manufactured from the mid 1950s onwards - but at first only as the new and larger No. 5 and No. 6 machines and as High Power and Dual Power versions of the others - the last models of the Dial Type series were very distinctive in appearance with one dial for speeds on the left-hand face of the main column and a very large feed dial fixed to the left-hand face of the knee. At the same time the control system was altered to reduce the number of levers and incorporate electrical push button control.
Heavily modified mechanically, and with a better specification, the standard (lower-speed) model was phased out. The High Power and Dual Power models had twenty-four spindle speeds (in a 100 to 1 ratio) spanning 16 to 1600 r.p.m on the No. 3 and No. 4 models and 14 to 1400 r.p.m. for the No. 5 and No. 6. Ordinary types were also improved and equipped much as the former High-Speed models with 16 speeds from 16 to 1600 r.p.m. (4 r.p.m. slower and 300 r.p.m. faster than before) and an increase in the number of feeds from 24 to 32 with a range that spanned from 3/8-inch to 90-inches of travel per minute. However, not all machines were equipped as per the catalogue specification and ordinary models of this era have also been found with twenty-one speeds spanning 20 to 1500 r.p.m on the No. 2 and 18 to 1300 r.p.m on the No. 3 and No. 4. With these improvements the Dial Types were now all capable of tackling not only a wider range of jobs, but also at faster rates of metal removal.