The bench holdfast, Fig. 40, is made of iron and is used to fasten down wood when being sawn or worked on in any way which requires it to be firmly held on the bench top. To use it the bench has a hole through which the straight part passes easily. The wood to be held is put under the lower end of the bent arm, and sufficient pressure is brought to bear by turning the screw.
Cramps are made both of iron and wood. The latter is generally a home-made article, and for most purposes is sufficient, but occasionally something more powerful is wanted, and the cabinet-maker is advised to have one, if not two, of iron. The general form is shown in Fig. 41, which represents a plain iron cramp. The wooden ones are similar in principle, the modifications being only such as required by the material. As the wooden cramps are seldom seen in tool-shops the cabinet-maker must either make them himself or get them made by a cabinet-maker or joiner. A good useful length is three feet and the cabinet-maker will rarely need anything larger. Instructions for making them will be found further on. The cramp is used for much the same purpose as the hand-screws when these are not large enough or cannot conveniently be applied.
Fig. 40.- Bench Holdfast.
Fig. 41 - Iron Cramp.