When driving a finish nail or casing nail into wood trim, it is often difficult, if not impossible, to drive the nail so that it is flush or slightly countersunk below the surface by using a hammer alone—at least not without damaging the wood. Overenthusiastic nailing results in half-moon divots created by the hammer, which can mar your baseboards, base shoe moldings, crown molding, and window and door case moldings. Such damage requires filling in the marks with wood filler, then sanding down the filler and painting the patch.
To prevent this kind of damage, the best technique is to stop just short of driving the nail completely, then use a nail set to finish the job. This small, inexpensive accessory extends your reach with the hammer, letting you strike just the nail—not the wood trim.
What Is a Nail Set?
A nail set is a small metal tool that allows you to hammer the finish nail flush to, or slightly below, the surface of the wood while keeping the hammerhead a safe distance away. The lower pointed end of the nail set fits into the divot on the head of a finish nail or casing nail, while the other end has a blunt head designed to be hammered. Because the nail set is made of heavy tempered alloy steel, it will not bend or collapse when hammered.
Nail Set vs. Power Brad Nailer
A collection of nail sets was once standard equipment in any carpentry toolbox, but owning a power brad nailer now eliminates the need for a nail set in many instances. Powered by a burst of air pressure, power brad nailers drive small finish nails (brads) so they are automatically countersunk below the surface of the workpiece, eliminating the need for setting the nails by hand. Power brad nailers are available in several types, included small corded electric nailers, battery-powered nailers, and pneumatic nailers that require an air compressor. Once used mostly by pros, a battery-powered brad nailer is now quite affordable and practical for homeowners.
A nail set is a good addition to your toolbox, even if you own a brad nailer. Oftentimes a nail gun will not set the nail head below the surface for various reasons, and a nail set helps in that case.
Can be used with large finish and casing nails
More expensive, but not prohibitive
Versatile nailing tool with many applications
Limited to small nails
A nail set is not usually regarded as a dangerous tool, but makers of hammers and other striking tools always advise users to wear eye protection when pounding nails or striking tools, such as chisels and nail sets. There is a small but real chance the tool could shatter, sending sharp shards toward your eyes. Hearing protection is also a good idea during any metal-on-metal hammering.
Wear a glove on the hand that is holding the nail set. If you do happen to accidentally strike your hand, the glove will soften the blow.
How to Use a Nail Set
Begin Hammering the Nail
Drive the finish nail or casing nail as far as you can without hitting the wood—usually about 1/4-inch to 1/8-inch away from the surface. Make sure to drive the nail with straight blows to avoid bending the nail. If you accidentally bend the nail, pull it and replace it.
Position the Nail Set
Place the round, pointed end of the nail set on the head of the finish nail or casing nail. These nails have a small divot on their heads to allow for placement of a nail set.
While not necessary, you may also find it helpful to switch to a hammer with a milled or checkered face for better contact between the hammerhead and the nail set.
"Set" the Nail
Gently tap the blunt end of the nail set with a hammer. Tap as lightly as is needed to drive the nail into the wood, increasing force only when necessary. One or two light blows of the hammer are usually sufficient. Drive the nail until the head is either flush or countersunk just slightly below the surface of the wood, depending on your finishing needs.
Fill the Nail Hole
If you intend to paint the wood, you may wish to leave the slight depression formed by the nail head unfilled. For an extra touch, though, filling the nail hole and sanding it down smooth yields a professional look. Wood putties are also available in various tints to match different wood finishes.
Keeping a Nail Set Clean
Wipe the nail set clean after each use. If the tool develops rust during storage, you can clean it with light machine oil applied with a scouring pad, then wipe the tool dry using a clean rag.
When to Replace a Nail Set
Replace a nail set if the pointed end loses its round shape from repeated use, or if the striking head develops a chip or crack.