This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
The ordinary carpenter's clamp (or cramp), shown in Fig. 287, is employed for tightening up the joints of boards, whether for the purpose of nailing or to allow time for glue to harden. It is composed of a long iron bar a provided with holes b at intervals for receiving iron bolts which hold the sliding bracket c; the length of slide of the second bracket d is limited by the screw e which actuates it. The length of opening varies from 3 to 6 ft. cost 25-38s.
Murphy's bench clamp, as sold by Churchills for 14s. 6d. is shown in Fig. 288. It is reliable, does not injure the work, is adapted to any thickness of bench top, can be changed to any position, and laid aside when not in use.
For simple rough work a suitable clamp can be made by driving wedges in to tighten up the work laid between stops on a plank.
A very useful corner clamp for securely gripping 2 sides of a picture frame during nailing or gluing together, is shown in Fig. 290. The two pieces being accurately mitred are placed in close contact and so held while the clamp is being tightened. These clamps are sold by Melhuish at 2s. a pair for taking 1 3/4-in. mouldings, up to 5s. for 4-in.
Fig. 291 shows a clamp designed for holding a circular-saw while being filed: a has 2 jaws, one of which is seen at b; they are of metal lined with wood, and are closed or unclosed by turning the handle c. The temporary mandrel of the saw may be placed in either of the holes of the clamp standards at d, so as to bring the saw to the right height in the jaws.
Bench clamps and holdfasts will be described under another section (p. 259).