Striking Tools

The striking tools look like the easiest part of the shop section, and they are, right up until a question asks which hammer to use on a chisel. The answer is almost always about the face: how hard it is, how it is shaped, and what it will do to the thing it hits.

Hammers

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The ball-peen is the shop's general metalworking hammer, and it is the right answer for striking a cold chisel or a punch. The rounded peen was originally for peening rivets - working the end of a rivet over to spread it.

A mallet is chosen for what it will not do. Rubber, rawhide, plastic or wood will not dent a finished surface or mushroom a soft part. A dead blow mallet has loose shot inside so it does not bounce back, which puts more of the blow into the work.

A framing hammer's milled face grips a nail head so it does not skid. It also leaves waffle marks, which is fine on framing lumber and unacceptable on trim.

Chisels

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Cold means the metal is not heated, not that the chisel is cold. That is the term's meaning and it gets asked.

A wood chisel is struck with a mallet, not a steel hammer. A steel face will split a wooden handle and damage the tool, which is why a mallet exists at all.

A chisel cuts because it is a wedge, which is the inclined plane lesson at work: a shallow angle gives a fine, easily driven edge, while a steeper one survives heavier work.

Punches

Each punch does a different job and the names are asked directly.

The starting punch and pin punch are a pair, and this is the topic's best question. A tapered starting punch is strong enough to break a stuck pin loose but cannot follow it far, because it soon becomes wider than the hole. A straight pin punch is slender enough to go all the way through but would bend if it took the first blow. Start with the taper, finish with the pin punch.

A drift punch does not remove anything. It lines up holes, which is why the question about aligning two bolt holes wants a drift.

Know it by sight

What you can skip

Across the 59 questions on this topic in our bank:

• Hammer variants by trade. Cross-peen, straight-peen and brick hammers never appear, and neither does the hatchet.
• Minor punches. The drift and the nail set come up once each, and the prick punch twice. The center punch is the one asked.

Where people lose points

Using a claw hammer on a cold chisel. A ball-peen is the correct tool.

Thinking a cold chisel is for cold-working only certain metals. Cold means unheated.

Driving a wood chisel with a steel hammer. A mallet.

Swapping the starting punch and the pin punch. Taper first, straight second.

Thinking a drift punch removes pins. It aligns holes.

Ignoring a mushroomed head. Grind it before it becomes shrapnel.

Work one in under a minute

A roll pin is seized in a shaft and must come out completely. Which punches are used, in what order, and why not just one?

A starting punch first, then a pin punch.

The pin is stuck, so the first blow is the hardest. A starting punch is tapered, so the shank behind the tip is thick and will not bend under that blow.

But the taper cannot follow the pin in. Once the punch has entered the hole a short way, its widening body meets the edge of the hole and it stops.

A pin punch has parallel sides the same diameter for its whole length, so it can travel as far as the pin has to. It could not have started the job, because a slender shank would bend.

Two tools because two different things are needed - strength at the start and reach at the finish - and no single punch has both.

Where this leads

The chisel is a wedge and the punch is a way of concentrating force into a small area, so both are the pressure and simple machine lessons in the hand.