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Mr BILLINGTON
Material Wasting - Chisel
WOOD LATHE
Chisels are sharp bladed tools designed for carving and cutting material. Although typically used for wood, any bladed object ground in a similar way could be known as a chisel. Chiselling involves the use of force, typically by a hammer, to force the bladed edge into material to cut it. The angle, size and shape of the blade depends on the application it is to be used for;
The 'bevel' chisel is most commonly found in wood workshops as they are the most versatile. They consist of a medium length flat blade with bevelled edges attached to a impact resistant plastic handle. The cutting angle is typically 25-30° and their shape makes them ideal for finishing dovetail joints as they can reach into the corner easily
The 'firmer' chisel has a blade with a rectangular cross section giving it greater strength and an angled bladed tip. They are considered the oldest form of chisel and are suited to cutting joints where a sharp 90° is required. They are typically used for heavier jobs due to their robustness
The 'pairing' chisel typically has a long thin blade connected to a handle via a tang. They are not designed to be impacted like the other two and should only be used by hand to move across the surface of timber for removing small amounts of material. The cutting edge is typically 20-25°
The 'mortise' chisel is the thickest of the 4 and has the largest angle of 30-40°. It is designed to remove chunks of material to form mortise joints typically through being impacted with a mallet. The blade thickness allows it to withstand heavy use and clearing out wood fibres from joints
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When using hand chisels it is important to keep hands well away from the bladed edge and out of the cutting path. The blade must be sharpened/honed prior to use using a polishing stone as a blunt chisel will struggle to remove material and increase the risk to the user of injury. Importantly, the work piece must be secured either with a clamp or vice before use. One hand should be use to support & guide the blade of the chisel whilst the other applies the force either by hand or using a mallet.
Thin pieces of material should be removed at a time to avoid splitting the wood and if the chisel begins to follow the grain a different direction should be attempted