Enter the product name, part number or cross-reference below...

Fasteners for Outdoor Applications

Fasteners for Outdoor Applications

When embarking on any outdoor project, from building a deck to a shed, selecting the right fasteners is crucial for ensuring the durability and longevity of your work. The outdoor environment exposes fasteners to various elements including moisture, high and low temperatures, and sun exposure. These things can cause deterioration in many materials. This article is meant to assist with selecting the best fasteners for your outdoors applications.

The Environment

Before selecting fasteners, it’s essential to consider the specific environmental conditions your project will face. Key factors include:

  • Moisture Exposure: Coastal areas, high rainfall, or projects near water (pools, sprinklers, etc.) require corrosion-resistant fasteners.
  • Extreme Temperatures: Change in temperature can cause expansions and contractions which will require a more durable and flexible material.
  • UV Exposure: Sunlight can degrade weaker materials over time. There are materials which are more UV-resistant that should be used if the fasteners is in the sun.

The Material

  • Stainless Steel: Stainless steel is always a good economical option for an exterior fastener. It’s corrosion resistant and readily available. It’s frequently used in coastal regions where saltwater accelerates rusting. There’s various grades of stainless steel which can be used including 18-8, 304, 316, 420, and many more. The higher grades including 316 are more resistant to corrosion.
  • Hot-Dipped Galvanized Steel: Hot-Dipped galvanized (aka HDG) are corrosion resistant. These can sometimes be more affordable than stainless and work well outdoors. They typically are not as corrosion resistant as stainless products are.
  • Silicon Bronze: Silicon bronze are high strength and resistant to corrosion. They’re commonly used in products designed for water such as boats.
  • Aluminum: Aluminum fasteners are lightweight and resistant to corrosion. They are not as strong as the above options but they are important to use when weight is a consideration.

Common Types of Fasteners used Outdoors

  • Screws: Screws provide a secure hold and can be offered in many of the corrosion-resistant materials listed above. Deck screws are often coated with a brown or green corrosion resistant finish and are commonly used for many wood-working projects outdoors.
  • Nails: Nails are typically easier to install but are not as secure as screws. The nails are often hot-dipped galvanized or stainless steel to deter rusting. An alternative option to standard nails are ring-shank ones which the rings prevent them from being as easily removed.
  • Bolts: Structural bolts are often galvanized and used in many outdoor projects. These usually come in an assembly with a nut and washer to secure it. A325 is the standard strength we provide but we can source others as required.


Many fasteners are available with various coatings and treatments to enhance their durability:

  • Zinc coating provides a basic level of corrosion resistance. Suitable for many outdoor applications but may not last as long in harsh conditions.
  • Ceramic Coating which offers protection against corrosion and is often used on screws for decks and other outdoor structures.
  • Anodizing is commonly applied to aluminum fasteners to increase their corrosion resistance and wear properties.

Additional Tips for Outdoor Projects

  • Drill pilot holes to prevent wood from splitting and make it easier to insert screws, especially in hardwoods.
  • Apply a sealant around fasteners to provide an extra layer of protection against moisture.
  • Periodically inspect your outdoor structures for signs of fastener corrosion or loosening, and replace fasteners promptly if you notice signs of wear.

You can select the right fastener by carefully considering the environment, materials, and project requirements. By selecting the proper fastener you can ensure that your outdoor project is secure and durable for many years. Corrosion-resistant fasteners may be a higher cost initially but it’ll save you time and money in the long run. If you’re ready to start finding your perfect fastener, please email our sales team with your requirements today at sales@knappfast.com.