Largest of the regular series-production Petermann automatics (it weighed just on two tons) the P25 was intended for the high-speed mass production of larger parts. However, the capacity was not large in an absolute sense, but only in comparison with the tiny components that the smallest lathe in the range, the P3, produced. Whilst the P25 could handle material up to 25 mm (1") in diameter but screwcutting was limited to a maximum of 11 mm (7/16") in steel or 14 mm (9/16") in brass.
Driven from a 6 h. p. 960 r.p.m. 3-phase motor, the six spindle speed spanned 350 to 3250 r.p.m. with 25 camshaft speeds (varying from 0.05 to 10 r.p.m.) available for each setting of the spindle speed. Normally supplied with a bell-cam to slide the headstock backwards and forwards (on its V-edge, taper-gib ways) the option was available of short-travel 40 mm (1.6") flat cam actuation. The maximum (bell-cam) travel when using a plain, non-adjustable work-support bush was 150 mm (5.9") but reduced to 100 mm (3.94") with the more complex and longer revolving type.
Built on lines common to most Petermann automatic lathes (though the No 10 was one important exception)  the headstock held a nitrided spindle running in a parallel-bore bronze bush positioned behind the spindle nose that could be adjusted by being drawn into its tapered housing. At the other end, a pair of high-precision contact ball races was fitted, capable of "micrometric" adjustment" with spindle end play taken up by ring nut. To reduce interference, an additional bearing was used to take axial pressure and belt tension from the overhung flat-belt drive pulley. The collet was drawn into its taper by balanced, roller-equipped toggle arms - these being mounted in a patented device that formed an oscillating support pivoting on the axis of two screws - the aim being to provide exactly equal toggle tension throughout the operating range from light to maximum grip (when the arms were on the top diameter of the ball-bearing-equipped spool.
Arranged radially around the spindle nose in the usual fashion, the five tools could each be operated independently with the pair set horizontally able to be set to work simultaneously. Each toolholder was equipped with the Petermann "micro-differential" apparatus where a first setting of the micrometer took the turning accuracy to within 0.01 mm of diameter and the second to within 0.001 mm (0.00004").
In addition to the usual attachments - single, double and triple-drilling units, a single thread-cutting attachment, a combined centring, drilling and threading unit and a screw-slotting device - a capstan-like turret accessory was available. This very special and superbly constructed unit also fitted the P16 and was designed to accept, in each of the six tool positions, either a stationary spindle or one driven by electro-magnetic clutching..

Five tools arranged radially around the spindle nose - whilst each could be operated independently the pair set horizontally could also be set to work simultaneously

Built on lines common to all Petermann automatic lathes, the headstock held a  nitrided spindle running in a parallel-bore bronze bush (1) positioned behind the spindle nose and adjustable by being drawn into its tapered housing. At the other end (2) a pair of high-precision contact ball races was fitted, capable of "micrometric adjustment" with the spindle end play taken up by ring nut (7). An additional bearing (2) was used to take axial pressure and belt tension from the overhung flat-belt pulley (8). The collet was drawn into its taper by balanced, roller-equipped toggle arms (4) - these being mounted in a patented device (6) that formed an oscillating support pivoting on the axis of two screws (8) - the aim being to provide exactly equal toggle tension throughout the operating range from light to maximum grip (when the arms were on the top diameter of the ball-bearing equipped spool

Although short jobs work could be turned without additional support longer items, as below, needed bushes fitting to the cutter frame. Three types were available - solid, adjustable stationary and revolving - to suit the nature, shape and length of the job.

Revolving Bush. Fitted with a pair of ball races, this was used for work demanding slightly less accuracy than normal it was useful in turning parts that were not round or made from hard materials such as nickel or stainless steel. A ring nut (1) allowed the split bush (2) to be closed down on the job

P25 Combined Centring, Drilling and Threading Attachment. This unit was driven by two belts, with the drilling spindle driven from that used for threading

P25 Single Screwing Attachment. Used for the external threading of small parts, the unit was driven by a flat belt through a old-fashioned fast-and-loose (ball-bearing suspended) pulley arrangement to give a form of clutched stop and start.

P25 Drill-on-Slide Attachment. Containing a nitrided spindle running in an adjustable bronze bearing at the front and a ball bearing at the rear (to better cope with thrust loads and the tension of the belt on the overhung pulley) this unit was designed for heavy-duty drilling operations

P7 Two-spindle Centring and Drilling Attachment: this unit allowed a part to be centred and then drilled. Two spindles were arranged side by side in a housing that could rocked from side to bring each into the working position. Only one spindle could be revolved, the other being used for centring.

P7 Three-spindle Centring and Drilling Attachment: this unit allowed a part to be centred and then drilled. Three spindles were arranged side by side in a housing that could rocked from side to bring each into the working position. Two spindles could be revolved, that in the middle and one at the front, the third being used for centring.