Unit 113: Maintain and use carpentry and joinery hand tools

Chisels

1. PowerPoint presentation Chisels Unit 113: Maintain and use carpentry and joinery hand tools

2. Aim Introduce learners to chisels. Objectives Identify at least two chisels. State at least one use for each chisel. List at least three parts of the chisel. State how a chisel is used. Select at least one chisel for a given scenario.

3. Types of chisels There are many types of chisels available, each one designed to be used for a specific purpose. The five most commonly used are: bevelled edge firmer mortice paring gouge. Image courtesy of www.workshopheaven.com . Reproduced with permission.

4. What determines the size of a chisel? The size of a chisel is determined by the width of the chisel blade. These sizes range from 3mm to 50mm. The most common are between 6mm and 25mm.

5. Parts of a chisel Shoulder Ground bevel Neck Ferrule Handle Blade Striking ferrule Image courtesy of www.shutterstock.com . Reproduced with permission. Modern chisels are manufactured to give versatility to the carpenter. All chisels have strong, machine-grade steel blades. However, as with all things, there are some chisels that are more expensive and of a better quality available.

6. Bevel-edged chisels The back of the blade is bevelled along both edges so that they can be used to cut in acute corners. Lightweight, suitable for paring. Available with with wooden, fibre glass or plastic handles. If a hammer is used on this type of chisel, it should be used with caution to avoid breaking the handle. Image courtesy of www.workshopheaven.com . Reproduced with permission.

7. Firmer chisels Used for general bench and site work. Blade is much stronger than a bevel-edged chisel. Can be used for paring or cutting joints. Can withstand light blows from a mallet, but care must be taken. If the chisel has a wooden handle, it may split due to repeated blows from a mallet. Image courtesy of www.workshopheaven.com . Reproduced with permission.

8. Mortice chisels Used for the cutting of mortices or slots which often form part of a joint. Strongly made to withstand heavy blows from a mallet. The blade’s thickness prevents the chisel twisting in the mortice or slot. The handle of this type of chisel can be wood or plastic. Some chisels have a leather washer incorporated to absorb the shock when struck with a mallet or hammer. Image courtesy of www.workshopheaven.com . Reproduced with permission.

9. Gouges Scribing gouge Firmer gouge A gouge is a chisel with a curved cutting edge. It is used to cut curved or contoured work. There are two main types of gouge: scribing gouge (in cannel) firmer gouge (out cannel) The cannel is the bevel, so: an in-cannel gouge is ground on the inside an out-cannel gouge is ground on the outside.

10. Gouges continued Scribing gouges are ground on the inside and are used for contour work where hollow or concave curves are required. This chisel is used to fit and scribe joints of moulded timber, eg in doors and windows. Firmer gouges are ground on the outside are suitable for any kind of scooping-out operation. These are sometimes called a carving gouge . Images courtesy of www.workshopheaven.com (left) and www.axminster .co.uk (right) . Reproduced with permission.

11. Any questions?