By the late 1960s Clausing lathes had become rather squarer in appearance, a styling and design change clearly seen in the 1968 Clausing 6900 Series machine illustrated and described below. The machine was based on a robust, flame-hardened, ground-finished bed that was well braced between elliptically shaped, rearward-draining, swarf-clearance holes.
Made in a forged, chrome-steel the headstock spindle had a hardened nose, was bored 13/8", and ran on precision Timken taper-roller bearings. Two types of collet fitting were available, a simple spring-collet assembly (which used either a hand-operated or lever-type draw tube) or the beautifully-well engineered English Burnerd Multisize collet set that ranged in capacity from 1/16" to 1". Each Multsize collet spanned a 1/8" gripping range and so could be used for both English and metric-sized material.
A more highly developed screwcutting and feeds gearbox was fitted to the 14-inch swing version of these lathes; while the 10-inch and 12-inch had an open base, the 14-inch enjoyed a sealed assembly with oil bath lubrication and dial and lever controls. A knob protruding from the headstock-end guard was used to select either fine feeds or screwcutting ratios.
The drive system on the 6900 Series  - the largest of the new Clausing range - was of the variable-speed type that gave from 52 to 2000 r.p.m. - with 26 to 280 r.p.m. in backgear and 180 to 2000 r.p.m. in direct belt drive. Speed changes were made hydraulically by a conveniently-positioned dial of the top of the headstock - a lovely idea for operator convenience and the speeding up of jobs, but just one more thing to go wrong in the future. A further model was also offered, the "High/Low", but this was just fitted with a 2-speed motor to give an improved selection of speed comprising two low ranges in backgear (on the slow motor speed) from 21 to 115 r.p.m. and 43 to 230 r.p.m. and two high ranges in direct drive (on the high motor speed) of 150 to 825 r.p.m. and 300 to 1650 r.p.m..