Senior's only small vertical miller, the "E-Type" used the No. 2 Morse taper, quill-feed S-Type head on a table and base unique to the model. Now a greatly sought-after machine it was, in Senior tradition, both beautifully made and finely finished - and took up a minimum amount of room. Although advertised as a "low-cost" machine, each was assembled and tested by one skilled toolmaker and, upon collecting a machine from the factory (after a cup of tea with Tom Senior himself) were invited to meet the worker responsible. However, it was, in fact, a relatively expensive item and retailed, in 1985, at £1,783 complete with a single-phase motor and mounted on the maker's stand.
Flange-mounted at the top, the 0.5 h.p. motor (1-phase or 3-phase) drove forwards by a Z-section V-belt to a spindle whose 2.5-inch travel quill was equipped with both fine and quick-action drilling feeds - the former being engaged through a cone clutch, exactly in the manner of that used on the Centec vertical head.. The spindle ran in precision-class Timken taper roller bearings (with a needle roller bearing at the tail) with early machines having four speeds from 480 to 2760 r.p.m. on a 3-phase supply and from 500 to 2,800 on 1-phase. Later versions had six speeds (though with the same speed range) - or a very effective electronic infinitely-variable speed drive unit. However, the option was available of a slower-running motor - 950 r.p.m. - though few can have been sold to such a specification. Simple but effective snap-on covers at each side of the head guarded the belt run - though the mechanism was far from cheap, with spring-loaded balls held within bronze housings,
Fixed at the base of the 3-inch diameter main column, the 26" x 6" (635 mm x 152 mm) table - which was an especially fine piece of work - had a travel longitudinally of 15 inches (381 mm); across of 6 inches (152 mm) whilst the swivelling head (keyed to the column, to retain its alignment) was raised and lowered by the handwheel at the back to give an effective vertical travel of 14.5 inches (368 mm). For an extra (breathtakingly expansive) £1037 the table could be fitted with power feeds from an electronically-variable speed control. Superbly engraved - and plated  in satin chrome - simple and reliable zeroing micrometer dials were fitted to all feeds.
By using special adaptors the S-Type head could also be mounted on other Senior milling machines - and became a popular fitting in small workshops where its handy size and sensitive movements allowed fine work to be carried out that would otherwise have needed a separate machine.
The overall height (with the motor extended fully upwards) was 80 inches with the base measuring, at floor level,  27.5 inches by 21.5 inches (699 mm x 546 mm). The weight was approximately 360 lbs ( 164 kg)..