Mechanick exercises, or, The doctrine of handy-works by Joseph Moxon.

¶ 5. Of Sockets, or Chocks, belonging to the Screw-Mandrel.

TO this Screw-Mandrel belongs so many Sockets as there are several sizes of Screws on the Shank. They are marked F5. in Plate 15. a the Socket, or Chock: b b, the Wooden Pin, c the Stay, d d the Notch to slip over the Male-screw.

These Hollow Sockets have Female Screws in them, made before the Notch to slip over the Male-screw of the Screw-Mandrel is cut. The manner of making Female-screws is taught Numb. 2. fol. 29, 30, 31. on∣ly instead of a Tap (used there) you use the several and different sizes of Screws made on the Screws-Man∣drel to do the Office of a Tap into each respective Socket; which Sockets being only made of Hard Wood, it will easily perform, though the Shank, or Axis, be but Iron.

Therefore (as aforesaid) to each of the Male-screws on the Screw-Mandrel is fitted such a Socket, that you

may chuse a Thread Courser or Finer as you please: But this Female-screw is open, or hath a Notch on one side of it, that it may slip over the Male-screw, and the Threads of each other fit into each others Grooves; and when they are thus fitted to one another, the fur∣ther or open side of the Male-screw is gaged in, or pin'd on the Female-screw with a Wooden Pin thrust through two opposite Holes, made for that purpose in the Cheeks of the Wooden Sockets, that it shake not.

When the Treddle comes down in working, and the Socket is fitted on its proper Screw, and pinn'd stiff upon it, and the Stay held down to the Rest of the Lathe, then will the Socket, and consequently the Stay slide farwards upon the Male-screws; so that a Tool held steddy on any part of the Stay, and applied to the out or inside of your Work; that Tools point will describe and cut a Screw, whose Thread shall be of the same fineness that the Screw and the Shank is of.