Why do my nails keep bending over instead of going in?

Hammering is a skill and it is almost never taught. The result is that most people push the hammer at the nail with a bent arm and a short grip, which delivers little energy and a lot of sideways deflection. Fixing the grip and the swing solves the problem far more reliably than buying different nails.

Step by step

1. Hold the hammer at the end of the handle.Choking up near the head feels controlled and is the commonest cause of bent nails. The length of the handle is what converts arm movement into head speed, and head speed is what drives a nail.
2. Swing from the elbow, with the wrist loose at the end.Let the head accelerate and let its weight do the work. Pushing with the shoulder produces a slow heavy blow that pushes a nail sideways rather than driving it in.
3. Hit the nail square on the head.The face of the hammer should arrive parallel to the nail head. A glancing blow puts a sideways force into a thin steel rod, which is exactly what bends it. Watch the nail head, not the hammer.
4. Clean the hammer face.Resin, glue, paint and grime on the face make it slip off the head. A few strokes on abrasive paper or a wire brush restores the grip, and it makes an immediate difference.
5. Use a hammer heavy enough for the nail.A light hammer on a large nail means many blows, each of them marginal, and every one is a chance to bend it. Match the hammer to the nail — a heavier hammer with fewer blows bends fewer nails.
6. Start the nail with light taps, then commit.Two or three gentle taps to set it upright and get it biting, then full blows. Trying to drive it fully from the first blow is where most bends happen.
7. Check what the nail is hitting.A nail that goes in straight and then suddenly bends has hit a knot, an old nail, a screw or a hard layer. Pull it, move 20mm, and try again rather than fighting it.
8. Blunt the point in splitty timber.A tap on the point with the hammer makes it punch through fibres rather than wedge them apart. It reduces splitting and, in dense timber, reduces deflection too.
9. Pilot in hardwood.In oak, beech and dense exterior hardwoods, a pilot slightly smaller than the nail is entirely normal practice, not a defeat.

Tips

• If you cannot hold a small nail safely, push it through a piece of card or hold it with long-nose pliers. Bent nails and bruised fingers come from the same problem.
• A nail that has bent once has yielded. Straightening and re-driving it will bend it again in the same place — take a fresh one.
• Nails go in more easily near the middle of a board than near its end, because the fibres near the end can move. That is also why the end is where they split.

Common mistakes

• Gripping the hammer just below the head — It gives control at the cost of nearly all the energy, so the nail is driven by many weak blows and every one can push it off line.
• Persevering with a nail that has already started to bend — The bend concentrates the next blow's force at the same point, so it folds further. Pull it and start again 20mm away.