d32 Threading Accessory. This was a unit used in place of the ordinary toolpost and in conjunction with the automatic saddle-reverse mechanism. It incorporated a semi-automatic feed where the operator only had to move the operating lever against a stop at each pass. To obtain an extra-fine finish, the overall rate of feed could be set by a rotary button, with the infeed cam so arranged that the finishing cuts were carried out with a rate gradually reducing to zero.