Coated Deck Screws vs Stainless Steel

Screws are essential tools in making outdoor structures, such as decks. In addition, they hold the structure and thus keep it sturdy despite heavy use and windy weather. However, few woodworkers research the best option between these wood fasteners, despite their crucial role. So, let us discuss Coated Deck Screws vs Stainless Steel.

Coated deck screws are black steel with a zinc coating. The black steel material rusts quickly once exposed to elements, and the coating acts as a tough protector. On the other hand, stainless steel does not rely on any coating for protection. It includes significant chromium amounts to add rust resistance qualities and improve durability.

Interestingly, it is possible for the zinc coating to wear out, creating a weak spot vulnerable to elements. Therefore, stainless steel comes in handy as it remains rust-resistance from the screw thread to the core. But this is not the only difference between these two fasteners. Check out this article for more!

Are Stainless Steel Deck Screws Worth It?

Stainless steel deck fasteners are the best choice for rust-resistant fasteners. They feature specific properties that allow them to withstand harsh environmental elements. In addition, the screws’ rust-resistance design makes them suitable for exterior wood projects and thus are worth it!

The primary difference between stainless steel screws and other fasteners is that they are solid stainless, while the others have a different coating material. Also, the material features a chromium-oxide, nickel, and titanium composition that keeps it intact from rust and corrosion.

On the other hand, coated fasteners depend on a chromium oxide coating for extra resistance against corrosion and rust. However, the coating deteriorates when contaminants settle on the screw’s surface. So, you are safer using stainless steel deck screws for outdoor projects.

Why Do Deck Screws Have a Coating on Them?

Deck screws usually have a coating on them to enhance their rust-resistance ability. Most manufacturers also add a chromium oxide layer that keeps the deck material safe from rust and corrosion.

In addition, deck screws have a significant impact on your deck’s longevity and appearance. Therefore, it would be best to pick a coated screw that does not deteriorate when chemicals interact.

Unfortunately, galvanized screws end up with black blotches when chemicals react. And even worse, the powdered galvanized coating may chip when driving them into the wood. Thus, the wood’s resin will reach the iron and speed up rusting.

It would be best to consider bronze or stainless steel screws for large applications, like deck building. The fasteners keep blotches from cropping up, maintaining the surface’s beautiful appearance.

How Long Will Stainless Steel Last Outside?

Stainless steel can last over a hundred years. But this duration lengthens or shortens depending on where and how you use it. In addition, we have various stainless steel grades, such as 304, 316, and 430, that constitute different measures of alloy metals. Thus, each type features a different lifespan.

The differences between these stainless steel types affect their durability and cost. Hence, it would be best to pick the best alternative depending on your project requirements and environmental conditions.

For instance, use 304 for projects with long-term exposure to harsh weather conditions. Also, although this grade does not have chloride resistance in 316, it is a more practical and economical option. Better still, 304 is perfect for most environments.

Are Galvanized Screws Good for Decks?

Galvanized screws are generally ideal for decks and other outdoor structures. However, it is best to avoid using them with pressure-treated lumber. Otherwise, the salt and moisture content in the air will compromise the screw’s integrity and longevity.

In addition, mechanically applied zinc screws have iron vulnerable to tannin acids in cedar and redwood. Even worse, these acids react with the iron and create a dark stain around the screw’s head. And thus, it is prudent to use stainless steel screws for the above wood types.

Fortunately, you can still get value from galvanized deck screws: the thicker the galvanized coating, the more durable the screw. So, ensure that your chosen deck has the correct coating level for the best result.

Also, remember that you may have a hard time working with hot-galvanized screws. The thick, globby layer clogs the threads and affects the screw’s recess, making it difficult to drive into the wood.

Finally, commonly available galvanized deck screws are either electro or mechanically galvanized. You can distinguish the two products by evaluating whether they have a shiny appearance.

For instance, electro-galvanized fasteners feature a shiny silver-color surface, whereas mechanically galvanized screws have a dull gray surface. Also, consider using mechanically galvanized screws for your exterior projects as electro-galvanized fasteners corrode quickly.

How Do I Choose Deck Screws?

While deck boards, railings, and posts are responsible for supporting items and people on the deck, deck screws hold the entire wood structure in place. Therefore, it is essential to consider the fastener’s features and their effect on the deck’s durability and quality.

Luckily, this section gives a detailed account of the essential factors to consider when getting a deck screw. Let’s take a look!

Material and Coating

Please check the screw’s material or protective coating when assessing various products. For example, alloy steel and carbon steel screws feature a waterproofing coating that keeps them safe during long humid summers and winters.

In addition, the weatherproof layer is perfect for seaside or lakefront areas with high moisture levels throughout the year. Thus, the screw’s material will remain sturdy for a long duration.

On the other hand, stainless steel fasteners are excellent for light deck boards as they naturally resist rust, moisture, and corrosion. So, you do not need a protective coating that may stain the wood.

Head Style

Most decks have flat heads. But there are several other screw head types that you can consider before choosing the best format for your structure. They include trim head, hex head, flat head, truss head, and round head screws.

  • Trim Head Screws. These are essentially flathead screws but with a much smaller head. Also, the head is completely flat and with a mall diameter, making the fastener ideal for decking.
  • Hex Head Screws. The screws have a hexagon-shaped head that needs a socket or wrench for tightening.
  • Flathead Screws. These tools have a completely flat head and are ideal for deck building. Moreover, the head can lay flush with the wood’s surface and won’t stick up later.
  • Truss Head Screws. The fasteners feature an extra-wide screw head. But they have a slightly rounded top that protrudes above the surface after fastening. 
  • Round Head Screws. These accessories feature a rounded screw head top and a flat screw head bottom, which sticks up from the surface after fastening. However, they are not ideal for decks because the protruding heads are a nuisance for those walking on the surface.

Drive Type

The drive type refers to the screw’s recess and the screwdriver type that can drive it into the wood. Select the most suitable and convenient drive for your project requirements and preferences.

In addition, take a look at these screw options to widen your perspective.

  • Phillips. The screws feature a cross-shaped recess and are one of the most famous drive types. However, they do not have the same driving torque or power as Torx and Robertson screws.
  • Slotted Screw Heads. These accessories have a slot running through the head’s center and are perfect for softwoods. But the slotted drill bit or screwdriver can slide from the screw’s recess and slow down the project. So, use it carefully.
  • Combo Screw Heads. The screws combine more than one drive type. For instance, the screw head may have a slotted and Phillips drive, giving the user more options.
  • Hex Screw Heads. These tools have a hexagonal recess that creates enough friction for the drill bit or screwdriver. Also, the drill does not slip during fastening and offers a smooth working session.
  • Robertson Screw Heads. These drive types are also known as square screw heads. They are easy to find and have a higher torque or driving power than other famous drive types. Thus, they are standard accessories in decking and readily available.
  • Torx Screw Heads. These screws are the best alternative for quick and effective deck installation. They feature a star-shaped recess with 12 sides that the Torx screwdriver grips. Therefore, you work with increased friction and grip strength. 


The correct screw thread helps speed up the project and delivers a solid and secure grip. Oppositely, the wrong thread can put a full stop on the deck or building project. So, always check the product description to know the threads-per-inch measurement.

Additionally, most deck screws have coarse or normal threads, and thus it would be prudent to check what the wood needs. For instance, go for a high thread count and fine threads when working with pressure-treated wood.

Also, you can consider working with a lower thread count if you have pressure-treated wood. The wood’s density makes it difficult to drive the screw into the narrow-spaced threads. And you may end up breaking the screw.


The standard deck screw’s length ranges from 1½ to six inches, depending on the size of your posts, joists, deck boards, and railings. Also, remember that the screw should penetrate entirely through the first wood piece and halfway through the other.

For instance, a six-inch screw should penetrate through a 4×4 post and then drive another two inches into the deck frame or joist. In addition, you can use two-inch and 1½-inch deck screws for securing joist hangers and ledger boards as they do not protrude out the wood’s surface.

On top of that, deck screws measuring three and 2½ inches are the most suitable for fastening deck boards, railings, and joists, whereas six-inch screws are the best for 4×4 posts.

Intended Use

Selecting suitable deck screws means getting your project’s correct fastener type and size. Hence, it is best to determine where and how you intend to use the accessories. Check out the screws below and the ideal situations to use them.

  • Structural screws are thicker and are perfect for securing load-bearing sections. So, you can use them to attach joists to ledger boards and fasten railing posts.
  • Non-Coated Stainless Steel Screws do not have a coating that stains wood after rain, snow, or sleet exposure. Thus, they are an excellent choice for light-colored lumber.
  • Trim Head Screws feature a smaller head and tighter threads that reduce composite tear-out issues. Hence, they are ideal for composite decking.
  • Lag Bolts or Lag Screws are primarily helpful when securing ledger boards or posts. The head is easy to drive into lumber and delivers a flush feeling and appearance.

Here’s How to Choose Deck Screw:

What Kind of Screws Do You Use for Pressure Treated Wood?

Fortunately, you do not need special fasteners for pressure-treated wood. However, you will get better results with galvanized steel, copper, stainless steel, carbon steel, and silicon bronze.

Below are more instructions about the screws.

  • Galvanized With Zinc

It would be better to hot-dip galvanized screws used with copper-treated lumber in molten zinc. Then, consider working with 850 degrees Fahrenheit for a better outcome. In addition, ensure that these fasteners meet the G-185 requirement for coating amount and ASTM A153 standard for zinc coating quality.

  • Stainless Fasteners

Grade 316 stainless steel screws are suitable for coastal areas, while grades 304 and 305 are perfect for copper-treated lumber in most areas. However, it would be best to avoid using stainless steel screws with galvanized structural connecters to avoid adverse chemical reactions.

  • Polymer-Protected

Polymer-coated screws rely on zinc plating covered with a non-reactive organic polymer to resist corrosion in copper-treated lumber. Also, the polymer layer acts like a plastic covering and keeps dissolved copper and water from reacting with the steel and zinc.

On top of that, here is a list of the most popular stainless steel deck screws to consider for your work.

  • Eagle Silver Stainless Steel Deck Screws. This product offers superior durability and is appropriate for deck planks. It has a flattened head, which blends into the deck perfectly and delivers a flawless deck.

The screw’s drive style is a standard Torx or star drive, and thus it is quick to install. In addition, the accessory facilitates a smooth fastening session, thanks to reduced screwdriver slippages.

  • SNUG SNG919 Tan Fence & Deck Screws. These deck screws offer more longevity and adhesion strength more than standard metal screws. Even better, the product package has screw 100 pieces.

In addition, the accessories feature an anti-corrosive coating that offers superior environmental flexibility. Therefore, they are perfect for both interior and exterior wood projects.

SNUG SNG919 screws have a flat top with nibs that helps it sit in level with the surface by countersinking it. Also, the stardrive system provides a fast torque and prevents cam-outs. So, you’ll enjoy a quick and safe installation session.

  • Kreg, Deck Screw (box of 700) SDK-C2W-700. These screws undergo an intense thermochemical heat treatment to increase their yield strength. So, they offer superior holding strength and are perfect for planks. 

Also, although the screws have a flattened head, they feature straightly sloped nibs that deliver a suitable amount of ground adhesion. Even better, they manage the likelihood of cracking planks during fastening.

On top of that, the accessories are available in multiple colors to accommodate multiple deck projects. And each screw features a tri-layered patented finish that resists corrosion from dampening and high humidity.

  • Hillman 48419 Deck Screws (Pack of 310). These screws have a ceramic-brown colored coating with four layers. The first layer is zinc, the second layer is adhesion chemicals, the third layer is an epoxy coating, and the final layer is a protective finish.

Additionally, the accessories have advanced countersinking nibs and a reinforced shank to reduce plank splitting during fastening. They also have a compatible star drive bit in the package for ease of use.

Lastly, Hillman 48419 boasts a specialized no-strip star drive technology that minimizes stripping, slippage, and cam-out issues. Even better, the system delivers a faster torque and enhances drive energy.

What Length Deck Screws Should I Use?

The deck screw’s length depends on the project. For example, ½ by six-inch screws are the best for attaching railing posts to the rim joist. Also, use one-inch six-gauge screws for hanging lateral joists from the rim joist.

Most decking screws are usually eight-gauge, whereas 1½ inches is the minimum length required to fasten deck boards to joists. In addition, it is best to use three-inch screws as they deliver extra holding power against upward shrinking pressure and warping boards.

Use 2½ screws to secure railing balusters and three-inch ones to attach stair treads to stringers or posts and stair treads. Also, consider having 1¾ inch accessories for stair risers and decking fascia.

Lastly, remember that specialty decking materials and supplies have varying requirements. For instance, ipe decking is quite challenging, and it would be better to use ten-gauge screws with smaller heads. Also, consider predrilling pilot holes to ease the work.

What Are the Different Types of Deck Screws?

The different types of deck screws vary depending on their head styles. The various versions include flat and bugle head styles, trim head, truss head, cup head or undercut, and hex head styles. Check the following section for more information.

  • Flat and Bugle Head Screws. These fasteners are the most commonly purchased screw types. Also, thanks to their versatility, the fasteners are popular in general construction and structural applications. And you can also use the screw head flush with the material or drive it deeper into the counterbore.
  • Trim Head Screws. The screws are suitable for finishing applications, like installing fascia boards on the deck or constructing the trim. In addition, the screw heads are smaller and deliver a more unobtrusive look with excellent holding power.
  • Truss Head Screws. These accessories have an extra-wide head with a small rounded design over the top. This way, the head can protrude above the surface during fastening. Even better, the screws have a wide surface underneath that guarantees superior security. 
  • Hex Head Screws. This product features a hexagonal head that helps distribute weight load to a broader area. In addition, you will enjoy working with an integrated washer that offers superior holding power.
  • Cap head or Undercut Screws. These screws are perfect for installing composite decking material to the deck frame. Also, they boast of a taller head that penetrates the deck’s outer cap stock.

Frequently Asked Questions

Here are some of the questions that you will likely interact with whenever you are discuss this subject:

  • What Is the Difference Between Galvanized Screws and Stainless Steel?

A galvanized screw appears to be very strong, but this strength may only be skin deep. In addition, the black steel underneath is susceptible to corrosion and rust despite the hard-wearing zinc layer.

On the other hand, stainless steel has a unique chemical makeup, giving it the power to withstand corrosion. In addition, the material has a hardness and strength that galvanized steel cannot match.

Stainless steel screws feature an incredibly high tensile strength of between 100,000 and 150,000 tensile pounds per square inch, while galvanized screws only have an average of 62,000 PSI.

Fortunately, you do not need that high tensile strength for ordinary woodworking projects. Therefore, galvanized screws can serve your basic project needs. All you need to do is ensure that the coating remains intact.

Galvanized fasteners deliver a dull, hardy, and industrial look, whereas stainless steel has a more refined look and is shinier. In addition, both products are perfect, depending on your project preferences. For example, galvanized screws win when it comes to cost, and stainless steel is perfect for superior strength and rust protection.

So, it is prudent to determine which factors are more important to you. Also, you can consider using galvanized deck screws in areas with minimum moisture exposure and corrosives. But remember, stainless steel is the safer alternative if you can spend more money.


Understanding the differences between various deck screws will help you choose the most suitable one for your work. Moreover, it will help adopt the best installation and maintenance strategies to deliver a perfect outcome. So, check out the debate:

Coated Deck Screws vs Stainless Steel

Coated deck screws have a zinc coating that helps them resist rust and corrosion, whereas stainless steel features significant chromium levels that keep it rust-resistant. Also, unlike stainless steel, which is ideal for any area, coated deck screws work best in areas with less moisture content. The zinc coating may wear down and expose the material underneath.

Fortunately, it is possible to get the maximum benefit from each fastener if they meet your project’s requirements. So, pick your screw material wisely.

Image of a woodworker wearing hearing protectors for woodworking

Tyron Otieno

Tyron is an avid woodworker and writer. He founded this website to help other woodworkers, whether hobbyists or professionals by sharing his knowledge and experiencie after a decade of woodworking.

Leave a Comment

Your email address will not be published.