How do I Determine the Appropriate Length of a Finish Nail?

Published on
March 3, 2023 at 2:29:16 PM PST March 3, 2023 at 2:29:16 PM PSTrd, March 3, 2023 at 2:29:16 PM PST

There are a variety of reasons you would need to use a finish nail. These include many indoor projects, like picture frames, shelving, and other small pieces. As you take a quick look at your options for a finish nail, you will soon discover that this isn't a very "quick" thing at all! There are quite a few different length options. So, the question becomes- how do you find the right length?

What Are Finishing Nails

Use finishing nails specifically for projects that require a clean, polished look. Unlike regular nails, they have small, barely visible heads, making them perfect for finish carpentry. This allows them to hold materials together without leaving noticeable marks, ensuring a smooth, professional appearance.Carpenters commonly use them in trim work, cabinetry, baseboards, and crown molding.

What is a Finish Nailer Used For?

A finish nailer is a tool designed to drive finishing nails into wood or other materials with precision. It ensures that you insert the nails cleanly without damaging the surrounding surface. This is especially useful for delicate woodworking projects, as it helps secure trims, paneling, door casings, and furniture assembly without splitting the wood. 

Using a finish nailer speeds up the job and improves accuracy, making it a must-have for professionals and DIYers alike.

What Size Are Finishing Nails?

Finishing nails come in various sizes, typically ranging from 1 inch to 3 ½ inches in length. The right size depends on the material you are working with and the type of project. Common sizes include:

  • 16-gauge finish nails – Stronger and more durable, ideal for baseboards, door casings, and chair rails.
  • 18-gauge finish nails (brad nails) – Thinner and less noticeable, perfect for delicate trim work, paneling, and small moldings
  • 15-gauge finish nails – Slightly thicker than 16-gauge nails, used for heavy-duty trim applications.


Finding the Right Length


To begin, it may help to know which lengths are the most popular. Although 6d (2”) and 8d (2 ½”) finish nails are more popular, that’s not what every single project requires. For this project, you're going to focus on length.

The letter "d" actually determines this, which is a bit confusing for some. In order to get your project done correctly, let's keep a few rules of thumb in mind:


#1 Understanding the "d"


Nails are typically sold according to penny size. This will look like 8d, 12d, or 16d. Penny sizing refers to the length of the nail. The higher the penny number, the longer the nail.


This sizing has been around for a very long time. It originated from the price of 100 nails centuries ago in England. For example, 100 8d nails used to cost 8 pennies and 100 16d nails cost 16 pennies. We no longer pay pennies for finish nails, but we stuck with the sizing. 


#2 Measure the Material You are Nailing Through


You always want to use a nail that is at least three times the length of the material you are nailing through. As a simple example, if you are nailing 1/2″ sheathing on an interior wall then you should use a nail that is at least 1 1/2″ long. The math is 1/2″ x 3 = 1 1/2″. 


#3 What if You're Nailing "to" and not "Through?"


There are occasions when you will want to use a nail that will penetrate the items you are nailing to and not through the other side. Let's use the same example of nailing together two pieces of 1/2″ material. In this case, you would need a nail that is 3/4″ long. This is because 1/2″ + 1/2″ = 1”. Using a 3/4″ in this application would prevent the nail from penetrating through the other side.


Order Finish Nails From Fastener USA


Whatever your needs and wants are, the finish nails you are looking for can be found and ordered from Fastener USA. Remember, you're not handling this project alone. There is really so much more to talk about when it comes to nails. If you're not sure exactly what you're looking for to make your DIY project a success, our team is always here to help!


More On This Topic

Brad Nail vs Finish Nail

Types of Finish Nails

What Size Finish Nails for Crown Molding?

What are Finish Nails Used for?

Best Finish Nail Gun

Finish Nail Gauge Chart

What Size Finish Nails for Baseboard?

What Size Finish Nails for Trim?

What Size Finish Nails for Quarter Round?

How to Remove Finish Nails?

Pin Nails vs Finish Nails