Chisels are cutting tools with a characteristically sharpened metal edge at one end designed to cut or shape metal, wood, and stone. A handle on the opposite end of the blade enables a firm grasp with one hand while allowing the other to strike using a handheld mallet. Industrial chisels use machines or a hydraulic ram to drive the chisel into a surface or structure.

Chisels were one of the first and fundamental tools used by humans. Archeologists have discovered rudimentary chisels made of flint and other forms of stone from as far back as 8,000 B.C. Dating back as early as the ancient Egyptians, copper and bronze tools closely resembling today’s modern metal chisels were used to work on wood and soft stone.

Entire sets of chisels were a must-have for craftsmen of wood and stone as well as general builders and artists throughout the pre-industrial age. However, the arrival of the Industrial Revolution did little to reduce the need for unique handheld chisels for many craft jobs. This fact remains, making chisels as essential today as they were hundreds of years ago. The same tools that gave life to iconic cathedrals or sculptural masterpieces are nearly unchanged in design and function for similar crafts today.

Operation

The sharpened blade edge of a chisel penetrates into wood, metal or stone by direct force of a hand, mallet, hammer or machine-powered ram. The length of the chisel creates leverage while the specialized contour of the blade edge lifts excess material from the newly expurgated area. The combination of the form and design of the blade edge works together to generate a wide variety of cuts or grooves in the affected material.

Types

Chisels fall in one of three broad categories: wood, metal and stone.

Within each class of chisel, there are countless sizes and blade shapes designed for different cutting and sculpting purposes.

Wood chisels

• Beveled edged chisels (bench and heavy duty)—beveled on the sides with a broad array of sizes, essential for woodworkers or cabinetmakers
• Butt chisels — a short chisel with beveled sides and a straight edge
• Framing chisel — similar to a butt chisel with a longer and more flexible blade
• Registered chisels — square sides instead of beveled and used more frequently in timber framing instead of woodworking
• Japanese bench chisels — similar to Western beveled edged bench chisels, having less beveling on the sides and harder edges to keenly cut softwoods without causing crumbling
• Mortise chisels (regular, sash and heavy duty)—thick and heavy chisels durably designed for use with a mallet on wood and levered out to remove waste in the process
• Paring chisels — light, long and thin for delicate shaving of small amounts of wood necessary for fitting joints
• Skew chisels — made with a 60° angle for work on trim and finishing
• Carving chisels — a family of chisels including gouge, parting, straight and V-groove used to make intricate designs
• Corner chisels — uses an L-shaped cutting edge to clean out square holes or corners with right angles
• Flooring chisels — designed to pierce and lift flooring materials
• Dovetail chisels — designed specifically to cut dovetail joints in woodLathe chisels—a large family of chisels designed with longer handles that provide more leverage to slash wood as it spins on a lathe

Metal chisels

• Cold chisels — a family of chisels ranging from fine engraving chisels to heavy duty. Struck with sledgehammers, removing waste metal from a piece of unheated metal
• Hot chisels — a group of chisels designed for use on metal softened by heat from a forge or torch

Stone chisels

• Standard and toothed stone chisels—used by sculptors and stonemasons to carve or cut stone, bricks and concrete slabs
• Spoon chisels — bent with a bevel on both sides and used by sculptors
• Brick bolsters — designed with a flat blade to cut as opposed to carving stone

• Masonry chisels — a set of heavy chisels used in demolition made with a dull head for wedging and breaking apart hard materials

Features

The most significant and diverse feature of chisels is the blade edge. The length of the chisel determines the amount of leverage available for use. The size of the blade allocates precision and delicacy. However, it is the shape of the blade edge that greatly impacts the desired result of a cut or groove produced by the chisel.

Materials

The vast majority of modern chisels are made with blades of steel with varying degrees of hardness associated with their particular purpose. However, assorted metals are used as alternatives. Handles come in a broad range of materials. Chisels not requiring repeated heavy impact have handles made of wood. Many chisels contain a foam, rubber or plastic grip around the handle area to absorb the shock produced when hammering.

Selection

For general home improvement, several different sizes of beveled edged chisels are adequate for most jobs. However, precise blade edge, shape and size are essential to specialty crafts such as sculpting, carving, furniture making and turning wood on a lathe. These crafts take years to perfect and correct chisel choice is a critical component of the apprenticeship.

Standards

Standards for chisels vary across each group and intended purpose. The steel used in cold chisels is tempered to produce levels of strength necessary for cutting through hard metals. Specifications for these chisels must be strictly adhered to in order to accomplish the desired result and keep a safe working environment.

Chisels designed for wood and stone do not require the same level of hardness as those intended for fashioning metal. However, stone and wood chisels have a greater degree of standards and specifications that create unique forms, edges and detailed cuts and grooves.

The manufacturer provides distinct details in all areas of the chisel's intended function. Due to the degree of specialty required in several crafts, expert advice and guidance from an experienced user of chisels for each group is highly recommended.

GOST - 1184 -- Woodworking chisels and gouges

ISO 2729 -- Woodworking tools, chisels and gouges

Image credits:

Isabelle Grosjean / CC BY SA 3.0