2. CLAMPING AND HOLDING DEVICES

3. INTRODUCTION Many devises have been designed to hold work securely while it is being measured or machined. Some of them are for one specific piece of work; others are of a more general nature. This include many types of clamps and vises.

4. C-Clamp – an all-purpose clamp made in the shape of the letter C. The jaw opening indicates the size.

5. Toolmaker’s clamp – (also known as parallel clamp) consists of two flat steel jaws which may be adjusted to fit a piece of work by means of a screw passing through the center of each jaw. It is used for holding small parts, both at the bench and at machines.

6. V-Blocks with clamps – either singly or pairs are used to hold cylindrical work, securely during the laying out of measurements for machine operation.

7. Bench vise – (the most favored kind for general shop work) usually swivel based securely fastened to the bench with bolts and the faces of its jaws are usually serrated and hardened to insure a firm grip on the work. The size of the vise is determined by the width of the jaws.

8. PROPER USES & MAINTENANCE Heavy hammering should not be done on bench vise. When it is necessary to hammer a work in a vise, it is best to support the work by placing a block of wood or metal under it to prevent the work from being driven down through the jaws of the vise.

9. Finished surfaces should be protected when place in the vise by using soft metal caps to protect the work from being damaged or marred.

10. The force of bending should against the fix jaws, rather than movable jaw of the vise. Heat from torch should not be applied to work held in the jaws, as the hardened insert jaws will then become soften.

11. Bench vise should occasionally be taken apart so that screw and nuts can be cleaned and lubricated.