A chisel is a tool used for carving materials, striking them with the aid of a hammer or mallet. Although it is a fairly straightforward mechanical tool that has been used for many years, it is still very commonly used today.
In fact, this tool was even used by primitive humans, when they were generally made from stone, but now they are manufactured using steel. Would you like to know more about this tool?
What Is Chisel?
A chisel is a wedged hand tool with a characteristically shaped cutting edge on the end of its blade, for carving or cutting a hard material (e.g. wood, stone, or metal).
The tool can be used by hand, struck with a mallet, or applied with mechanical power. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it (such that wood chisels have lent part of their name to a particular grind).
Chiselling use involves forcing the blade into some material to cut it. The driving force may be applied by pushing by hand, or by using a mallet or hammer. In industrial use, a hydraulic ram or falling weight (‘trip hammer’) may be used to drive a chisel into the material.
A gouge is a type of chisel that serves to carve small pieces from the material; particularly in woodworking, woodturning and sculpture. Gouges most frequently produce concave surfaces and have a U-shaped cross-section.
How to Use a Wood Chisel?
A sharp wood chisel can cut mortises, shave rough surfaces, chop out corners and scrape off glue. We’ll demonstrate these techniques and show you how to sharpen your chisel. The wood chisel is an indispensable member of your toolset. We’ll show you how to get the most out of it.
Technique 1: Mortise cuts
Face the bevel down. Push or tap the back of the chisel to remove thin slices. Control the depth by raising and lowering the handle.
Start recesses or mortises by outlining the area with a sharp utility knife or by making a series of shallow chisel cuts perpendicular to the surface. Skip this step and you risk chopping wood outside the mortise. Then remove thin slices by tapping the chisel with a hammer, bevel side down, to carve out the wood inside the perimeter.
Chiseling with the grain can sometimes have disastrous results. If the grain runs deeper into the wood, it’ll direct the chisel too deep. Stop and chisel from the opposite direction if you feel this happening.
Technique 2: Paring cut
Pare thin slices of wood to flatten the bottom of an open recess. Keep the back of the chisel flat on the wood. For easier slicing, pivot the chisel as you cut to move the blade in an arc.
If the recess is open on one side, like a hinge mortise, flatten the bottom by paring off thin slices with the back, unbeveled side of the chisel held flat to the wood.
In general, when you’re shaving into a piece of wood, face the bevel down. When you’re flattening a cut and have access from the side, face the bevel up and hold the back of the chisel tight to the surface.
Technique 3: Chopping cut
Chop out large Amounts of wood by slicing off small amounts with each cut. Strike the chisel with a hammer and chop down about 1/2 in. Then chisel from the end to remove the piece before continuing. Your chisel must be sharp for this cut.
Caution: Wear safety glasses.
Set the chisel alongside one cut edge and strike it sharply with a hammer to remove wood from notches. This isn’t fine work; the cut will be hidden by another board.
Technique 4: Chop and pare
Cut a groove, or dado, by first sawing along both edges to the desired depth. Then break out the wood in the middle with your chisel. Space the chisel cuts about 1/2 in. apart.
Chisel out dadoes and other more precise joints a little at a time with a series of shallow cuts rather than driving the chisel too deep. Use a hammer or mallet for rough work or press with the heel of your hand for lighter cutting chores or finer cuts.
Technique 5: Scraping
Scrape glue joints or other imperfections from wood projects by holding the blade at a right angle to the wood with the back of the chisel facing you. To remove thin shavings, support the blade with your fingers and press down while you draw the chisel toward you.
Scraping requires a perfectly flat, sharp edge. The chisel tip should scrape cleanly without leaving scratch marks in the wood.
Types of Chisels
#1. Woodworking chisels.
Woodworking chisels range from small hand tools for tiny details, 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 progresses to smaller tools to finish the detail.
One of the largest types of chisels is the slick, used in timber frame construction and wooden shipbuilding. There are many types of woodworking chisels used for specific purposes, such as:
- Firmer chisel has a blade with a thick rectangular cross section, making them stronger for use on tougher and heavier work.
- Bevel edge chisel can get into acute angles with its beveled edges.
- Mortise chisel thick, rigid blade with straight cutting edge and deep, slightly tapered sides to make mortises and similar joints. Common types are registered and sash mortice chisels.
- Paring chisel has a long blade ideal for cleaning grooves and accessing tight spaces.
- Skew chisel has a 60-degree cutting angle and is used for trimming and finishing across the grain.
- Dovetail chisel made specifically for cutting dovetail joints. The difference being the thickness of the body of the chisel, as well as the angle of the edges, permitting easier access to the joint.
- Butt chisel short chisel with beveled sides and straight edge for creating joints.
- Carving chisels used for intricate designs and sculpting; cutting edges are many; such as gouge, skew, parting, straight, paring, and V-groove.
- Corner chisel resembles a punch and has an L-shaped cutting edge. Cleans out square holes, mortises and corners with 90-degree angles.
- Flooring chisel cuts and lifts flooring materials for removal and repair; ideal for tongue-and-groove flooring.
- Framing chisel usually used with mallet; similar to a butt chisel, except it has a longer, slightly flexible blade.
- Slick a very large chisel driven by manual pressure, never struck.
- Drawer lock chisel an all-metal chisel with 2 angled blades used for tight spaces, like cutting out the space for fitting a desk drawer lock.
#2. Metalworking chisels.
A chisel set is for metalworking projects. Cold chisels can carefully scrape excess material from soft metal pieces. The flathead can cut through metal sheets or shave notches through the surface with its resilient steel construction.
When punching holes in aluminum, try using a chiseling tool that narrows to a precise point and strike the device with a hammer to puncture metal.
Chisels used in metalwork can be divided into two main categories: hot chisels and cold chisels.
2.1 Hot chisel
A hot chisel is used to cut metal that has been heated in a forge to soften the metal. One type of hot chisel is the hot cut hardy, which is used in an anvil hardy hole with the cutting edge facing up. The hot workpiece to be cut is placed over the chisel and struck with a hammer.
The hammer drives the workpiece into the chisel, which allows it to be snapped off with a pair of tongs. This tool is also often used in combination with a “top fuller” type of hot cut when the piece being cut is particularly large
2.2 Cold Chisels
Cold chisels are used to cut heavy metal that cannot be cut with a saw or shears, usually because space is limited. They are also used for any number of repair jobs, such as cutting off rivet heads or slicing through rusted nuts and bolts, and other heavy work.
Before machine tools became available, cold chisels were more widely used in general engineering. Metal components were often made as close to the final size as possible by casting so that most of the work in shaping the metal was done by the furnace.
Cold chisels were then used to cut away material from the areas of the casting that needed to be brought to an exact size. These areas were then finished by filing and scraping.
Cold chisels are made from carbon tool steel, which is usually octagonal in cross-section. Tool-steel is used as it can be hardened to form a hard and tough cutting edge.
To make a cold chisel heat the end of the bar of tool steel until it is bright red and hammer to the desired shape.
You will need to reheat the bar several times as it cools quite quickly when you hammer it. If you don’t have a blacksmith’s anvil you can use the face of a large sled hammer instead (if the face is not too scarred).
Clamp the sledgehammer in a large vice to keep it steady. Don’t strike to face of the sled hammer with your forging hammer or you may knock off chips of hardened steel which can damage your eyes.
Once the end of the bar has been hammered to the right shape you can grind the cutting edge as shown in the diagram. Harden the bar and then temper it to make the edge tough so that it does not crack. Different materials will require slightly different edge grinding and tempering.
#3. Stone Chisels.
With so many types of stones for sharpening, it can be difficult to determine what the best stone is for your woodworking needs. Fortunately, the variety of stone materials will allow you to select a material that will meet your needs and stay within your budget.
The three main types of bench stones are oil stones, Waterstones, and diamond stones. Since every woodworker’s needs and preferences are different, understanding the advantages of each stone will allow you to be a more informed purchaser of sharpening stones.
3.1. Oilstones
Oilstones are traditional stones that have been popular for years. Today they are available in man-made and natural stones. The man-made stones are made of either silicon carbide or aluminum oxide abrasives. These are generally available in coarse, medium, and fine grades.
The natural stones are made of novaculite and are available in grades such as Soft Arkansas, Hard Arkansas, and Hard Translucent Arkansas; the harder the grade, the finer the grit of the stone. Natural stones are generally finer grits than man-made stones so it is common to have both man-made and natural oilstones in your sharpening kit.
3.2. Waterstones
Waterstones has become very popular among woodworkers because they cut faster than oilstones. Like the oilstones, Waterstones is available in both a man-made and a natural variety. However, in the western world, man-made stones are significantly more popular.
Most Waterstones are made of aluminum oxide abrasive. While this is the same type of abrasive material as used in some oilstones, the stones are quite different. First, unlike oilstones, Waterstones use water to remove the swarf.
Using water makes it easier to clean up and more convenient to use. Secondly, Waterstones cut faster than comparable oil stones because the binding material that holds the stone together is softer.
The softness of the stone allows the stone to cut faster because sharp new material is constantly being uncovered. However, the softness is also the biggest disadvantage of the Waterstone because it must be flattened regularly.
3.3. Diamond Stones
Many woodworkers are catching on to the advantages of diamond stones for some good reasons. Unlike oil and water stones, diamond stones are all man-made. These industrial diamonds are applied to a metal backing to create an abrasive surface.
The diamond stone can be extremely versatile. It can be used to sharpen any woodworking tool. It can even sharpen carbide-tipped router bits that both oil and water stones can’t touch.
Diamond stones do not wear unevenly because the diamond surface is so hard. Because of this diamond stones can be used to flatten oil and water stones.
#4. Masonry Chisels.
Masonry chisels are typically heavy, with a relatively dull head that wedges and breaks, rather than cuts. Often used as a demolition tool, they may be mounted on a hammer drill, jackhammer, or hammered manually, usually with a heavy hammer of three pounds or more. These chisels normally have an SDS, SDS-MAX, or 1-1/8″ Hex connection.
Some masonry chisels are designed for cutting soft stone, while others will stand up to harder use.
Like brick chisels, masonry chisels are generally used only to score the stone; as with glass cutting, the task involves scoring first, then breaking along the scoreline. Gentle taps on the chisel create the scoreline, allowing the stone to be snapped off when the line has been completed.
Floor chisels are another variety of chisels that can be used to scrape floors, clear off blobs of concrete, and do other rough chisel work.
Types of masonry chisels include the following:
- Moil (point) chisels
- Flat chisels
- Asphalt cutters
- Carbide bushing tools
- Clay spade
- Flexible chisels
- Tamper
A plugging chisel has a tapered edge for cleaning out hardened mortar. The chisel is held with one hand and struck with a hammer. The direction of the taper in the blade determines if the chisel cuts deep or runs shallow along the joint.
What Size Chisels Do I Need?
If you live in America and are going to be getting the majority of your wood from your local home center, you’re going to want two sizes:
- 3/4 inch chisel
- 1/4 inch chisel
The reason for this is if you’re going to be joining two pieces of wood together (with mortise and tenons or dado joints) a good rule of thumb is you want the adjoining piece to be 1/3 of the thickness of the main case piece.
So if we were to get one chisel the same width as the main piece of wood (3/4 inch) and one chisel that’s the same width as the adjoining piece of wood (1/4 inch) then we would have the toolkit that we need to join these two pieces of wood together.
Sometimes it’s helpful to have a larger chisel that you can wail on and remove a lot of wood with and a wider chisel, such as 1 1/2 inch, is really helpful, but not necessary at the outset.