Choosing chiselling tools
The list above is what exists. This is how to decide which of it you actually need, what separates a tool worth keeping from one that ends up at the back of a drawer.
Which face goes against the wood
A chisel has a flat back and a bevelled front. Bevel down, the flat back rides the wood and the bevel lifts the shaving away, so the cut runs shallow and controlled. Bevel up against the work, the wedge drives itself deeper the harder you push.
Paring a joint flat means bevel up with the flat back on the reference surface, so the back becomes the guide. Chopping waste out of a mortise means bevel facing into the waste so the wedge pushes the chip toward the space rather than into the wall you want straight.
- Flat back is the reference
- It rides the surface you want flat. That is what keeps a paring cut from diving.
- Bevel toward the waste
- When chopping, so the wedge pushes the chip into the space rather than the good side.
- It dives if you push
- Bevel down against the work, the harder you push the deeper it goes. That is the wedge working.
- Short cuts, not long
- A chisel that has gone off line will not come back within the same cut. Reset and go again.
Sharp is not optional
A dull chisel needs force, and force is what makes it skid off a line or split the timber ahead of the edge. A sharp one is pushed by hand and goes where it is pointed, which means sharpening is a control issue rather than a finish issue.
The back has to be flat as well as the bevel keen. A back that is not flat behind the edge means the edge is not straight, and a honing guide is worth having simply because a consistent angle sharpens faster than a freehand one you keep re establishing.
- Flatten the back
- Once, properly, on a new chisel. The back is half the edge and it never needs doing again.
- 25 then 30 degrees
- A ground primary and a small honed secondary. Only the secondary needs touching up.
- Honing guide
- Removes the angle from the list of things to get right, so honing takes a minute.
- Strop between cuts
- A few strokes on loaded leather keeps an edge that would otherwise slowly go.
What to hit it with
A wooden or resin mallet spreads the blow over a broad face and does not mark the handle. A steel hammer concentrates it, which splits a wooden handle and, on a chisel not designed for it, mushrooms the end into a burr that will eventually break off.
Masonry and metal chisels are the exception: they have hardened struck ends and are meant for a club hammer. Their mushroomed heads should still be ground back, because a spalled edge on a struck face throws fragments.
- Mallet for wood chisels
- Broad face, softer material. It spreads the blow and leaves the handle intact.
- Never a claw hammer
- A steel face on a wooden handle splits it. On a plastic one it mushrooms into a burr.
- Club hammer for masonry
- Those are designed to be struck hard and have hardened ends for it.
- Grind a mushroomed head
- A spalled struck face throws steel fragments. Ten seconds on a grinder fixes it.
Wood, masonry and metal are separate tools
A wood chisel is hardened to hold a very keen edge, which makes it brittle. Used on brick it chips instantly. A masonry chisel is tougher and softer, ground blunter, and cannot be brought to a paring edge at all.
A cold chisel for metal is different again: a stout blunt wedge that deforms steel rather than slicing it. Using any one of the three for another's job either destroys the tool or does the job badly, and usually both.
- Wood, hard and keen
- Holds a paring edge, chips if it meets masonry or steel. Never struck with a hammer.
- Masonry, tough and blunt
- Survives a club hammer and brick. Cannot take a fine edge and does not need one.
- Cold chisel, blunt wedge
- Deforms steel to split or cut it. Roughly 60 degrees, on purpose.
- Do not swap them
- The three are metallurgically different tools. Using one wrong ruins it in a stroke.
Both hands and where they are
A chisel goes where it is pointed and keeps going. The rule is the same as carving: nothing you own is on the far side of the edge, and the work is clamped so no hand is holding it in line with the cut.
Masonry chiselling adds fragments. Brick and concrete spall sharply and travel, so eye protection is not conditional, and a hand guard on the chisel shaft prevents the injury that happens when the hammer misses.
- Clamp the work
- Both hands on the chisel, one pushing and one braking. That is how an overrun gets stopped.
- Nothing beyond the edge
- It goes where it points. Assume it will travel further than intended, because sometimes it does.
- Eye protection on masonry
- Concrete spalls and travels. This is the one place people are consistently caught out.
- Hand guard
- A rubber collar on a masonry chisel for the blow that misses. It will miss eventually.
Frequently asked questions
- What are the different types of chisel?
- Three families that are not interchangeable. Wood chisels are hard and keen for paring and chopping joints. Masonry chisels are tough and blunt for brick and concrete under a club hammer. Cold chisels are stout wedges for cutting and deforming metal.
- Which way should the bevel face when chiselling?
- Flat back against the surface you want flat, so the back becomes your guide. When chopping waste out, turn the bevel toward the waste so the wedge pushes the chip into the space rather than into the wall you are trying to keep straight.
- Can I hit a wood chisel with a hammer?
- Not with a steel hammer. It splits a wooden handle and mushrooms a plastic one into a burr that eventually breaks off. Use a wooden or resin mallet, which spreads the blow. Masonry and cold chisels are different: those have hardened ends made for a club hammer.
- What angle should a wood chisel be sharpened to?
- A 25 degree primary bevel from grinding, with a small 30 degree secondary bevel honed on it. Only the narrow secondary needs touching up, which takes a minute rather than ten. Softer paring work can go a little shallower, chopping a little steeper.
- How do I sharpen a chisel?
- Flatten the back first on a coarse stone, once, on a new chisel: the back is half the edge. Then hone the bevel on progressively finer stones with a honing guide holding the angle, and finish on a loaded leather strop. Strop between cuts rather than resharpening later.
- Why does my chisel keep wandering off the line?
- Usually a dull edge, which needs force, and force makes it skid. Otherwise it is bevel direction: with the bevel against the work the wedge drives itself deeper the harder you push. Also take short cuts, since a chisel that has left the line will not return within the same cut.
- What chisels do I need to start with?
- Four bevel edge wood chisels at 6, 12, 18 and 25mm covers most joinery. Add a mallet, a sharpening stone and a honing guide, because a set that cannot be sharpened is worse than three that can. Masonry chisels only when there is masonry to cut.
- What is a cold chisel used for?
- Cutting and shaping metal cold, without heat. It is a blunt wedge at around 60 degrees that deforms steel to split it, so it cuts rivets, bolts and sheet, and shears off anything that will not undo. It is far too blunt to cut wood and would only split it.
