Are Deck Screws Strong? Wood Screws vs. Deck Screws


Screws are important construction tools that come in varying shapes and sizes. Since screws are mostly used to join parts, people tend to assume that all screws are the same, such as the commonly confused deck screws and wood screws, which are similar in appearance but ideal for different functions. What’s the difference, and are deck screws strong?

Deck screws are stronger than wood screws and are often made from copper or stainless steel. Their corrosion-resistant properties make them ideal for outdoor use. On the other hand, wood screws are mostly made from steel and have a flat head as well as an unthreaded shank that make strong joints.

Are you looking to learn more about screws? Buckle up for you are in the right place. In this read, we’ll pit deck screws against wood screws and construction screws, discussing their main features, similarities, and differences.

Wood Screws vs. Deck Screws: The Differences

As one of the most confusing screw types, you’ll need to be extra careful when shopping to ensure that you choose the right screw for your needs. Below are the main differences between deck and wood screws: 

Screw Heads

The deck screw and wood screw have similarly flattened and countersunk heads. The deck screw, however, has a larger surface area designed to increase its capacity to hold heavy loads. Deck screws also have flare or bugle shaped heads that help to prevent the screws from sinking into the material.

Unlike deck screws, wooden screws don’t have the bugle shape. This means that over time, wood screws will eventually sink into the material, consequently causing splits or cracks.

Shank

Deck screws have uniquely threaded shanks that increase their durability, more so when used outdoors in wet areas. The shanks have a sharp threading and an aggressive point that work together to increase the hold of the screws once put in place. Deck screws hold firm primarily due to the adequately-threaded and tapered shank.

Wood screws, on the other hand, don’t have fully threaded shanks-and the threads aren’t as deep either.

Since the shank isn’t fully threaded, you should expect some challenges when looking to insert the screw inside your wooden material.

Threading

Deck screws are known for their sharp and conveniently deep threadingOpens in a new tab. that easily cuts into an item, ensuring the screw firmly secures itself.

Despite being threaded, wood screws aren’t as sharp as their counterparts. You’ll also find that the reduced tapering will minimize the efficiency of the wood screw over time.

Therefore, if you’re after effortless bonding and efficiency, you should consider using deck screws over wood screws.

Construction Material

Deck screws are usually made from copper, stainless steel, or galvanizedOpens in a new tab. steel, which enhances the durability of the screws, more so when used in wet environments. The use of stainless steel and copper in manufacture increases the corrosion-resistant properties of deck screws, thus making them ideal for outdoor use.

Wood screws are made from steel, which isn’t strong enough to withstand rainy conditions or extreme humidity. As a result, wood screws tend to rust and wear out over time when used on outdoor structures.

For more info, check out our Will Deck Screws Rust article for a complete guide on screw materials and how to prevent corrosion.

Which One Should You Use?

Deck screws are ideal for outdoor use due to their stainless steel makeup, which prevents rust while increasing resistance to corrosion.

Compared to wood screws, deck screws are better suited to neutralize corrosion elements such as rain, humidity, and salty water. And since wooden screws are mostly made from steel, they won’t cope well when exposed to these elements.

Therefore, using deck screws is advisable for outdoor projects. On the other hand, wood screws can come in handy when working on light, indoor projects.

Here’s an informative video covering the best types of screws for different projects involving wood.

Deck Screw vs. Construction Screw

Although similar in appearance, construction screws are usually larger compared to deck screws. Construction screws are ideal for large scale applications due to their large sizes.

While deck screws are mostly made from stainless steel or zinc, construction screws are usually made from coated materials. The coatings help to increase rust resistance while also reinforcing the strength of the construction material.

You’ll also find that most construction screws have high shear strength to allow for smooth joining of both soft and hard surfaces. 

Advantages of Deck Screws

These GRK ScrewsOpens in a new tab. (link to Amazon) are one of the most popular because of their well known quality and and assortment of screw types available.

Deck Screws Are Flare Shaped

Deck screws have a bugle or flare shape, which helps prevent the screw from sinking into the wood, minimizing the risk of cracks or splitting.

Deck Screws Have Sharp and Deep Threading

The deep and sharp threads allow for ease of use, consequently increasing efficiency when working on wood boards.

Deep Threading on the Shank

Deck screws are ideal for holding heavy pieces of wood in place. The sharp and well-tapered threading, combined with the aggressive tip, ensure that deck screws can be drilled into surfaces with relative ease.

Durability

Deck screws can withstand the test of time, more so in salty, rainy, and humid conditions without rusting.

Since they are mostly made from stainless steel and galvanized metals, these screws come packed with corrosion and rust-resistant properties, making them a must-have for outdoor construction.

Frequently Asked Questions About Deck Screws

Are Deck Screws Galvanized?

Deck screws are known for their rust and corrosion-resistant properties, which makes them ideal for outdoor structures. Some deck screws are made from stainless steel or copper, while others are galvanized to increase their lifespan.

Point to note; you should select galvanized deck screws with caution since they aren’t ideal for all surfaces.

For instance, a galvanized deck screw will deteriorate if used on pressure-treated lumber due to chemical reaction. Using stainless steel or bronze coated deck screws is advisable for big projects such as building decks.

Are Deck Screws As Strong as Nails?

Deck screws are strong fasteners and even boast of superior tensile strength compared to nails. While it might be tempting to compare these handy devices, they all have their advantages and ideal applications.

For instance, nails are perfect for attaching joistsOpens in a new tab. and stair stringersOpens in a new tab. compared to deck screws. However, screws are the better option when attaching railings and decking to the framing. Either way, for a sturdy and robust deck, you’ll need to use both nails and deck screws.

What Is the Shear Strength of a Deck Screw?

The shear strength of a deck screw depends on several factors such as:

  • Length
  • Thread type
  • Screw quality
  • Insertion technique
  • And the force used on the screw (lateral or withdrawal forces).

The longer the screw, the better it will hold the surfaces being joined into a unit.

Deck screws are not designed to resist shear like bolts and bolted joints are. That being said, most screws can hold between 75-125 pounds with more quality deck screws being able to hold above 200 pounds per screw. You can also double up the screws to hold more weight.

You should also consider the type of thread if you want your deck screw to work well. For instance, coarse threads, due to the increased space between each thread, will hold strong when used on soft surfaces.

A fine deck screw works better when joining hard surfaces. Fine screws have tighter threads that allow for increased grip, thus leaving your unit compact and strong.

Wrapping It Up

Deck screws are among the strongest and most convenient screws you can use for your outdoor projects. The flare shape and the deep, sharp threading make deck screws highly efficient and ideal for long term use.

Now that we’ve compared deck screws to wood screws and even construction screws, you should have a better understanding of screws in general.

Before buying a specific type of screw for your DIY projects, consider factors such as the project size and location. For humid and extremely salty or rainy environments, deck screws will serve you well.

However, you can use wood screws to tackle your light indoor projects since the screws won’t be directly exposed to corrosion and rust agents.

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Robert Sampson

I'm Robert Sampson and I live in Colorado where I spend a lot of time in the backyard with my family either grilling, playing games and sports, or working on a project to make our backyard a better place to be.

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