Nails come in many shapes, and the right one depends on how much load the joint carries and how visible the head will be. Thick, strong nails suit structural work, while thin ones suit trim where you want a small hole to fill. Match the nail to the job and to the wood you are using.
Common Nail Types
| Type | Typical use | Notes |
|---|---|---|
| Common | Framing and rough carpentry | Thick shank, flat head, strong hold |
| Box | Light framing and boxes | Thinner than common, less likely to split |
| Finish | Trim, mouldings, cabinets | Small head to be set below the surface |
| Brad | Delicate trim and small parts | Very thin, holds lightly, often used with glue |
| Roofing | Shingles and felt | Wide head to hold flexible material |
| Masonry | Fixing into brick or block | Hardened steel; wear eye protection |
Length and Thickness
A common rule is that a nail should go through the thinner piece and penetrate well into the thicker one, with much of its length in the receiving piece. Check the plan or a trusted building guide for specific requirements. If the project is structural, such as a deck, roof or frame, follow local building rules and the plans rather than a general rule of thumb.
Coatings and Materials
- Bright steel: usually for dry indoor use.
- Coated or dipped steel: made to resist rust for exterior work. Check the maker’s guidance.
- Stainless steel: suits damp areas and some timbers that react with other metals.
- Ring-shank and spiral nails: extra grip for subfloors and decking, harder to pull out.
Hammering Without Damage
- Choose a hammer weight you can swing in control.
- Hold the nail near the head or use a small piece of card for tiny nails, so your fingers are away from the strike.
- Tap lightly to set the nail, then move your hand away and use full strokes.
- Keep the hammer face and nail head in line so the nail goes in straight.
- For hardwood or thin boards, drill a small pilot hole to avoid splits.
- Use a nail set on finish nails to sink the head slightly, then fill the hole.
- Wear eye protection, as nails can bend or fly.
If you use a nail gun, follow its manual and keep your hands clear of the nose and the work area.
Reading Nail Sizes and Package Labels
Nail packaging uses a few terms that confuse first-time buyers. Length is usually given in inches or millimetres, and some regions also use a traditional “penny” size, written with a d, where a larger number means a longer and thicker nail. The scale is a convention, so read the actual length printed on the box rather than relying on the number alone.
The label should also tell you the type, the material, the finish and sometimes the gauge, which is the thickness of the shank. A lower gauge number generally means a thicker wire, though check the maker’s explanation because conventions vary between tool and nail types. Thin nails are less likely to split wood but hold less, while thick ones grip well but can split thin boards or the ends of a plank.
Look for notes on intended use, such as interior, exterior, framing or trim. A box that says it is suitable for pressure-treated timber, for example, is telling you something specific about the coating. If the packaging does not make the intended use clear, check the maker’s listing or ask the seller. Buying a mixed assortment is handy for a first toolbox, but for a real project it is better to buy the correct type in the correct length.
Choosing by the Material Being Fixed
Different materials behave differently under a nail, so match the nail to the wood and the board thickness.
- Softwood framing: common or box nails work well, and the wood is forgiving. Follow the plans for length and spacing.
- Hardwood: dense timber can bend nails and split, so drilling a pilot hole is a good habit. A slightly thinner nail may help.
- Plywood and sheet panels: panels vary in thickness, so check the recommended nail type and edge spacing for the product you are using.
- Thin trim and mouldings: finish or brad nails leave a small hole, and a dab of glue improves the hold.
- Brick, block and concrete: use nails marked for masonry, and wear eye protection because the hardened steel can chip.
- Plasterboard: special drywall nails or screws are normally used, so follow the board maker’s guidance.
Keep nails well back from the edge of boards, and stagger them rather than placing several in one grain line, which reduces the risk of splitting.
Indoor Versus Outdoor Nails and Corrosion
Using the wrong finish outdoors is a common reason for streaks, rust stains and failed joints. Bright steel nails are fine in dry rooms but can rust quickly in damp areas or outside. For exterior jobs such as fencing, cladding and decking, choose a nail whose packaging states that it is made for outdoor or exterior use.
Timber that has been treated with preservatives can react with some metals, so check the preservative maker’s guidance and the nail’s labelling before you buy. Stainless steel is often chosen where appearance matters, near the coast or with timbers that stain easily. Coated nails resist weather but the coating can be scratched during driving, so avoid unnecessary bending and re-striking.
Mixing metals in the same joint, for example nails in a metal bracket, can cause corrosion over time in damp conditions. If you are fixing hardware, use the fasteners the hardware maker recommends. For anything structural outdoors, such as a deck frame or a pergola, follow local building rules and the plans rather than a general rule of thumb.
Hand Nailing Versus Nail Guns
For a few repairs and occasional projects, a hammer and a small selection of nails is all you need. It is cheap, quiet and gives you a feel for the material. You also have more control over delicate trim, because you can stop and adjust easily.
A nail gun speeds up large jobs such as framing, fencing or installing lots of trim. Nails for guns are collated into strips or coils and are not interchangeable with loose nails, so match the nails to the tool exactly as the manual states. Different guns are made for different tasks, from heavy framing to light brad work, and the gun must suit the nail type you chose.
Nail guns bring added risk. Read the manual, wear eye and hearing protection, keep your free hand away from the nose of the tool, and disconnect it from power or air before clearing a jam. Never point the tool at anyone or disable its safety features. If you only expect to use one for a weekend project, renting or borrowing may make more sense than buying.
Storing, Handling and Fixing Mistakes
Store nails in a dry place in labelled containers, such as small jars or divided boxes, so you can find the right size quickly. Damp storage causes rust, which makes nails harder to drive and can mark the wood. Keep them out of reach of children and pets, and sweep up dropped nails promptly.
When a nail goes in crooked or bends, do not keep hitting it. Pull it out with the claw of the hammer, using a small block of scrap wood under the head to protect the surface and improve leverage. If a nail is hard to remove, pliers or a nail puller can help. Fill the hole as needed.
If you often split boards, check whether the nail is too thick, too close to the edge or being driven into dry hardwood without a pilot hole. Blunting the tip of a nail slightly by tapping it can help in some cases, but a drilled pilot hole is the more reliable cure. Finally, keep a small magnet or magnetic tray in the workshop to pick up stray nails before they end up under a foot or a tyre.
FAQ
Nails or screws: which should I use?
Nails resist side force and go in quickly, while screws pull parts together and can be removed. Many projects use both, depending on the joint.
How do I stop wood from splitting?
Use thinner nails, stay away from board ends, or blunt the tip slightly. Pilot holes also help.
What does the "d" mean on a nail box?
It stands for penny, a traditional sizing scale in which a bigger number means a longer nail. Since conventions vary, check the actual length printed on the box.
Can I reuse old nails?
Straight, clean nails can sometimes be reused for rough work. Bent or rusty ones are better discarded, especially for visible or structural jobs.
Should I use glue as well as nails?
For trim and small parts, glue plus nails is a common combination, with the nails holding the piece while the glue sets. Use the glue type recommended for your material.
What is a nail set used for?
It is a small metal punch that drives a finish nail head just below the surface so the hole can be filled. It avoids denting the wood with the hammer.
Are galvanized nails suitable for all outdoor work?
They suit many exterior jobs, but some treated timbers or conditions call for another material. Check the timber maker's guidance and the nail packaging.
How far apart should nails be spaced?
It depends on the material and the job. For structural work, follow the plans or local building rules, and for decorative trim follow the product instructions.
Can I use a nail in plasterboard?
Special drywall nails or screws are made for this. Follow the board maker's instructions on spacing and depth.
The Short Version
Choose nails by type, length and coating to suit the work and the setting. Drive them carefully with eye protection, and follow plans, the nail maker’s advice and local building rules.