Choosing the Right Fastener (Part 1 Nails)

Choosing the right fastener for your home improvement project can be daunting. Should you use a screw or nail? How long does it need to be? Galvanized? Hardened? Brass? So many options means lots of ways to make a mistake.

I’ll walk you through the most important points and help you make the right choice when it comes to your next project. There are countless specialty fasteners that will defy the details I’m going to talk about here. This post is about general carpentry uses and a few of the more useful specialty fasteners. Today, we’ll talk about nails and next week we will dive into finding the right screw for the job.

What Length Nail Do I Need?

This has got to be the most common question when it comes nail selection. Every building code requires different things so you are best to check your local rules and regulations. That being said, there are two prevailing rules of thumb to help you determine proper nail length.

• Rule of Thumb #1 – Use a nail that is at least 3 times the length of the material you are nailing through. For example, if you are nailing 1/2″ sheathing on an exterior wall you should use a nail that is at least 1 1/2″ long. 1/2″ x 3 = 1 1/2″.
• Rule of Thumb #2 – Use a nail that will penetrate the item you are nailing to (not through) at least 3/4″. So, to use the same example of 1/2″ sheathing you would need a nail that is 1 1/4″ long. 3/4″ + 1/2″ = 1 1/4″.

Whatever length you use, you can’t really overbuild. If you are going to err on nail length, always err on the side of using too long of a fastener rather than too short. Just remember, you don’t want your nails being too long that they blow out the back side of your work.

Understanding Sizing

Nails are sold according to penny size. 8d, 12d, 16d where ‘d’ stands for the penny from the British monetary denomination. This sizing has been around for a loooong time and originated from the price of 100 nails centuries ago. For example, 100 8d nails used to cost 8 pennies and 100 16d nails cost 16 pennies. Penny sizing refers to the length of the nail. The larger the penny number, the larger the nail.

There is another type of sizing that relates mainly to nails for pneumatic nail guns (specifically finish nailers). Fasteners for nail guns are sized according to gauge (ga.). From largest to smallest, you have 15-ga., 16-ga., 18-ga., 21-ga. and 23-ga. Unlike penny sizing, gauge refers to the thickness of the nail and not the length. You can have various lengths in each different size gauge. For example, you can buy 15-ga. nails in lengths from 1″ to 2 1/2″.

• 15 & 16-ga. Nailers – Called finish nailers, are the largest nails and typically used for applications like door/window jambs, baseboards, large crown molding and fastening other significant pieces of wood that are not structural.
• 18-ga. Nailers – Called brad nailers, shoot smaller nails than their 15 & 16-ga. cousins. They don’t have quite as much holding power but they are better for smaller trim because they don’t leave as big of a nail hole and also lower the risk of splitting delicate trim pieces.
• 21 & 23-ga. Nailers – Called pin nailers. These nails are usually so small they have no head and therefore minimal holding power. These are best used for holding very small pieces of trim with the assistance of glue. Of all the nailers in my arsenal I use these least.

If you’re looking for a good all around nailer, then I’d suggest the 18-ga. for its versatility.

There are other nail guns that are for specific uses like framing nailers, roofing nailers and siding nailers. These nailers work much the same way as finish nailers but they shoot larger nails that are appropriate for the different applications they represent.

Interior or Exterior

If your project is going to be exposed to the elements, then your fasteners need to be up to the task. You can’t use interior nails on the outside and expect them to last very long. Interior nails will rust and bleed through the paint and eventually fail. So, there are four types of exterior nails that you’ll need to know.

1. Electro-Galvanized – These are steel nails that are given a thin coating of zinc to add rust resistance. This coating is kind of the bare bones of rust prevention. In my opinion, electro-galvanized nails give you a few more months or possibly an extra year before the rust sets in. They are an option, but not one that I recommend.
2. Hot-Dipped-Galvanized – These are steel nails again that are dipped in molten zinc during the manufacturing process. This creates a much thicker coat of zinc that has plenty of staying power to prevent rust for many, many years. These are also the recommended fasteners for pressure treated wood and cedar which can cause standard nails to corrode quickly.
3. Stainless Steel 304 – If you want the premium product that is guaranteed not to rust, that would have to be stainless steel. Be aware that you’ll pay a big premium for stainless nails. The number 304 refers to the blend of alloys in the steel that make it have those amazing stainless properties. For most exterior applications 304 is the most appropriate grade of stainless you’ll need.
4. Stainless Steel 316 – This is the mac-daddy of exterior fasteners. 316 steel has chromium, extra nickel and added molybendum (whatever that is) mixed in with the steel to make sure it can stand up to the most brutal conditions. If your project is being built on the coast where it will be subject to salt water spray or other conditions that are particularly rust inducing, 316 stainless is what you need.

Shank Patterns

There is a nail for every task. And a different shank pattern for many tasks as well. Here are a few of the most common and what you would use them for.

1. Common – This type of nail your standard all-around nail. It has a smooth shank and no frills. From framing walls, to attaching trim (pneumatic nails are almost all smooth shanks) this is your baseline nail.
2. Coated (Sinker) – I use these nails most often for framing when I’m not using a framing gun. They have a thinner diameter than common nails and a thin coating on them that when subjected to the friction of driving a nail allows them to sink into the wood more easily, hence the name “sinkers.” That same coating when it cools functions a bit like a glue to hold the nail in place.
3. Ring – Ring shanked nails are my favorite for installing wood siding and roof decking. Anything that needs extra holding power to protect against strong winds and uplift is a good candidate for ring-shanked nails. The ringed shank adds significant holding power to help keep the nail in place.
4. Spiral – These are excellent nails for use with hardwoods. They spin as they are driven which gives them additional holding power over a common nail and its spiral shank helps prevent splitting wood.

There is really so much more to talk about when it comes to nails, but I don’t have time for an encyclopedia-like post here. This should be a good primer to cover the most important things you need to know when it comes to finding the right kind of nail for the right job. If you have any doubts about which nail to use, you should always check with your local building codes since their requirements can vary across the country.

Feel free to comment here with any questions you might have about which nail is best for your project and I’ll answer in the comments below.