Chisel
A chisel is a tool for carving and/or cutting a hard material such as wood, stone, or metal. A chisel, typically made of hardened or tempered steel, or more rarely, common steel, consists of a sharpened end (called the blade) attached to a straight handle. The handle and blade of some types of chisels are made in one piece.
In use, a worker forces the chisel into the material to cut the material. The driving force may be manually applied or applied using a mallet or hammer. In industrial use, a hydraulic ram or falling weight ('triphammer') drives the chisel into the material to be cut.
A gouge, one type of chisel, is used, particularly in woodworking and sculpture, to carve small pieces from the material. Gouges are most often used in creating concave surfaces. A gouge has a 'U'-shaped cross-section.
Types
Chisels have a wide variety of uses. Many types of chisels have been devised, each specially suited to its intended use. Different types of chisels may be constructed quite differently, in terms of blade width or length, as well as shape and hardness of blade. They may have wooden handles attached or may be made entirely of one piece of metal.
Woodworking chisels
Woodworking chisels range from quite small hand tools for tiny detail, to large chisels used to remove big sections of wood, in 'roughing out' the shape of a pattern or design. Typically, in woodcarving, one starts with a larger tool, and gradually progressing to smaller tools to finish the detail. One of the largest types of chisel is the framing slick, used in timber frame construction.
Lathe tools
A lathe tool can be a woodworking chisel designed to cut wood as it is spun on a lathe. These tools have longer handles for more leverage, needed to counteract the tendency of the tool to react to the downward force of the spinning wood being cut or carved.
Metalworking chisels
Chisels used in metal work can be divided into two main categories, hot chisels, and cold chisels. A hot chisel is used to cut metal that has been heated in a forge to soften the metal.
Cold chisel
A cold chisel is a tool made of tempered steel used for cutting 'cold' metals, meaning that they are not used in conjunction with heating torches, forges, etc. This tool is also commonly referred to by the misnomer 'coal chisel'. Because cold chisels are used to form metal, they have a less-acute angle to the sharp portion of the blade than a woodworking chisel. This gives the cutting edge greater strength at the expense of sharpness.
Cold chisels come in a variety of sizes, from fine engraving tools that are tapped with very light hammers, to massive tools that are driven with sledgehammers.
Hardy chisel
A Hardy Chisel is a type of hot chisel with a square shank, which is held in place with the cutting edge facing upwards by placing it in an anvil's Hardy hole. The hot workpiece cut is then placed over the hardy, and struck with a hammer. The hammer drives the chisel into the hot metal, allowing it to be snapped off with a pair of tongs.
Stone chisels
Stone chisels are used to carve or cut stone, bricks or concrete slabs. To cut, as opposed to carve, a bolster chisel is used; a wide, flat blade that is tapped along the cut line to produce a groove, then hit hard in the centre to crack the stone. To increase the force, stone chisels are often hit with Lump hammers, a heavier type of hammer.
See also
External links
- Sharpening Chisels and Planes provides detailed instructions on how to properly sharpen chisels.