Many novice DIY homeowners are not aware how important it is to choose the right size nail when nailing items together. You should choose a nail that is three times as long as the thickness of the material you are nailing together. If you want to nail a ½ inch drywall to a wall stud the length of the nails should be at least 1 ½ inches long (3 x ½ inch).

This is a reasonable guide most of the time. When nailing very thin materials into wood, a minimum of ½ inch of penetration is required. If the thin item is holding a heavy item such as a metal bracket that will hold a heavy item such as a hanging flower pot, the nail should penetrate 1 ½ to 2 inches.

If you are nailing something through drywall or other soft wall covering, the thickness of the wall covering should be added to the optimal nail length because this material does not offer very much additional holding strength. To nail a ¾ inch thick wooden shelf support to drywall you should use nails no shorter than 3/4 + 1/2 + 1 1/2 = 2 3/4 to 3 inches.

For common nails, box nails, and finish nails are measured in pennies, the symbol being the letter small "d". Most carpenters have difficulty remembering the penny sizes. For penny sizes see the following chart.

2d = 1 inch

3d = 1 1/4 inches

4d = 1 1/2 inches

5d = 1 3/4 inches

6d = 2 inches

7d = 2 1/4 inches

8d = 2 1/2 inches

9d = 2 3/4 inches

10d = 3 inches

12d = 3 1/4 inches

16d = 3 1/2 inches

20d = 4 inches

30d = 4 1/2 inches

40d = 5 inches

There are also specialized nails for different types of materials. Drywall has its own nails as well as pressure-treated wood, roofing shingles and vinyl siding. Some nails have very wide heads to hold soft materials in place, such as Styrofoam sheathing. Some have very small heads so that they can be set below the surface of the wood and hidden with a filler material such as finishing nails. In addition there are nails that are coated with rosin or that have rings or twists in them to increase their gripping strength.

Nails are made out of several different kinds of metals to include aluminum, iron, steel, and rustproof stainless steel. Some are coated with zinc, known as galvanized nails, to be rust resistant. Some are hardened by heat so that they can be hammered into very hard materials such as cement nails. There are also duplex nails that have a doubled-head for easy removal in temporary work. There are also special nails for hardwood flooring, upholstery, and for concrete.

In addition, there is an entire different category of nails used in power nailing guns. Nail guns are driven by electricity or compressed air. Nail gun nails are manufactured in strips for loading into the nail gun. Nail guns are used to install delicate moldings, install roofing and ruff construction of the house frame. They generate a great amount of power and must be treated with caution and respect.

Always select the right nail length and type for the material you are nailing together. Nails that are to short or are the wrong type for the material will fail causing the material to become loose.

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