There are a lot of different materials and coatings used for decking screws. The right screw for you depends on the environment you are installing it in.

Blackhawk Protect

Sourced for Australia’s harsh conditions, Blackhawk Protect uses a patented tri-level coating process. This creates a chemical barrier against the formation of rust. Along with conforming to AS 3566.2 Class 3, Blackhawk Protect has advantages like:

• Superior corrosion (rust) resistance over non coated/galvanised fasteners
• A unique layering process reduces the risk of any damage to the coating when the screw is scratched
• Less risk of premature corrosion due to reactions with other metal types

Blackhawk Protect is suited for general external applications that are exposed to the weather.

Stainless Steel

Stainless steel has a different chemical composition compared to carbon steel screws. This composition makes stainless steel corrosion resistant. There are different levels of stainless steel which changes their corrosion resistance.

304 Stainless Steel

By far the most common version of stainless steel, 304 is suitable for applications that come in frequent contact with water. 304 stainless steel:

• Protects the screw from corrosion (rust) in most external applications
• Has an attractive silver finish
• Is the material of choice for most decking professionals

304 Extreme Stainless Steel

304 Extreme stainless steel offers greater corrosion resistance than standard 304 stainless steel. This is achieved through an increase of copper during the manufacturing process.

316 Stainless Steel

316 stainless steel is the highest grade of stainless steel found in decking screws. 316 stainless steel:

• Offers the greatest resistance from corrosion
• Can be used in sever environmental conditions
• Has an attractive silver finish
• Can be used in close proximity to salt water bodies like the ocean and swimming pools

If you are unsure of what environmental factors may affect your project, it is always best to go for the highest grade possible. “It is better to have it and not need it, then need it and not have it”

There are a number of environmental factors that can contribute to premature corrosion of fasteners. These factors can be, but are not limited to the following:

• Preservative treated wood
• Soils
• Poor quality decking oil or decking paint
• Salt water or salt air carried from a salt water body

It is recommended that you discuss this with your builder or local council prior to commencing work.

Blackhawk has made choosing the right screw easy for you. Check out our Blackhawk Calculators page to find out exactly what you need.

Designed with the user in mind, Blackhawk wanted to create a package that added value to the decking experience. After reviewing the traditional method of packaging fasteners, Blackhawk realised that there was a better way to do it.

It started with the idea of being able to reuse the packaging rather than throw it away. Screw packaging is generally strong and durable. So what better way to reuse it than to make it into a storage bin. This is when the hook was integrated into the back. The generic sized hook fits onto most styles of hangers on the market so it will fit straight into existing storage set ups.

The foldable lid locks into place once opened. This makes getting to the screws, or whatever you store in them afterwards, as easy as possible. The lid also locks into place tightly when closed reducing the risk of losing the screws all over the back of your ute.

A first of its kind in screw packaging, the underside of the lid has an integrated driver bit holder. If you have ever cut yourself on a screw point trying to get the driver bit out from the bottom of the tub, you will understand why this is such a great feature.

With Blackhawk Fasteners, not only are you getting great fasteners, you are getting a package that helps you work!

"Visit the PRODUCT CATALOGUE to see the range of fasteners available in the Versi-Tubs"

The screw material is one of the most import factors when making your purchasing decision. Getting this wrong can have a huge impact on the strength and durability of your deck. Blackhawk Protect uses a high-grade, tri-layer coating process. These layers are joined together through a chemical process which results in a tightly bonded coating on the screw. Along with conforming to AS 3566.2 Class 3, Blackhawk Protect has advantages like:

• Superior corrosion (rust) resistance over non coated/galvanised fasteners
• A unique layering process reduces the risk of any damage to the coating when the screw is scratched
• Less risk of premature corrosion due to reactions with other metal types

Blackhawk Protect is environmentally friendly as it does not contain hazardous substances like lead, cadmium and mercury including hexavalent and trivalent chromium.

There are a number of environmental factors that can contribute to premature corrosion of fasteners. These factors can be, but are not limited to:

• Salt water and salty air carried from a salt water body
• Preservative treated wood
• Soils
• Poor quality decking oil or decking paint

Blackhawk recommends that you discuss the environmental factors in your area with your builder or local council prior to commencing work. Blackhawk Protect is not suited for applications within 5km of a salt water body.

Decking screws require a great amount of torque to drive and other head types can lose grip. This can cause the screw head or the driver bit to be damaged.

Decking screws also require countersunk heads. This is so they drive themselves into the decking board and finish flush, or just under the face of the board. Blackhawk Decking screws have integrated ribs under the head to help remove debris that is caused by the screw driving into the timber. This gives a better finish and reduces the risk of timber splinters getting stuck under the head.

Blackhawk has made choosing the right screw easy for you. Check out our Blackhawk Calculators page to find out exactly what you need.

To find out what screw point is right for you, first you need to answer the following questions:

• Are you using metal joists?
• Are you using hardwood decking boards or joists?
• Are you going to pre-drill?

Listed below are the common screw points used for decking applications and what applications they are suited to.

Type 17 Point

This is the most common type of decking screw point. It refers to the long cut section at the point of the screw. The type 17 point:

• Helps to remove debris when being driven through the decking timber
• Drives through the timber easier than a needle point screw

Drill Point:

Drill point refers to the sharp, drill like point at the end of the screw. The drill point:

• Cuts into the timber creating its own pilot hole
• Reduces the need to pre-drill your decking boards
• Can pre-drill into a greater number of timber species, including most hardwoods

Different species of decking timber have different hardness levels. This will determine the need for pre-drilling. You can check the hardness level of your timber by going to the timber hardness page. BLACKHAWK recommends that you always pre-drill the ends of the decking boards as they are prone to splitting.

Winged Point:

Winged point refers to the sharp, drill like point at the end of the screw. The winged point also incorporates two wings that protrude out from the screw and look like ears.

The winged point:

• Cuts into the timber creating its own pilot hole, allowing the screw to spin more freely. This makes it easier for the screw to drive through the metal
• Eliminates the need to pre-drill the metal joists
• As the winged point incorporates a drill point, it can pre-drill into a greater number of timber species, including most hardwoods

Once the wings drive through the timber and make contact with the metal, the wings break off. This allows the thread of the screw to create a thread in the metal joist. It then tightens the decking board to the metal joist.

Blackhawk has made choosing the right screw easy for you. Check out our Blackhawk Calculators page to find out exactly what you need.

This guide shows a variety of species and some of their different characteristics. Please note because timber is made from a natural product, each piece is different and may vary from the results listed below. Please use this as a guide only and speak to your timber supplier for more information.

Hardwood / Softwood

Timber that is used in the building and construction industry can be separated into two groups: Softwoods & Hardwoods. Timber merchants often refer to timbers that are easy to work with as softwoods. However, softwoods are not always a softer material than hardwoods. Strength is better determined by the density of the timber. Hardwood and softwood are actually categorised by the way they reproduce.

Hardwood (Angiosperms) – Hardwood trees flower and have seeds that form in ripening fruit or shells. They are deciduous which means they lose their leaves each year. They are typically denser than softwoods because they are slower growing. There are thousands of species of hardwoods.

Softwood (Gymnosperms) – Softwoods usually produce seeds that are uncovered in cone-like structures. This is where the name “Conifers” (a major source of softwoods) comes from. There are around 600 different species of softwoods.

Density – Green & Dry

The density of timber is determined by the weight of a set sample size. In Australia, kilograms per cubic meter (kg/m3) is used. The higher the density, the more difficult it is to work with. Less than 480kg/m3 is considered very soft. Between 480kg/m3 and 560kg/m3 is soft. Anything over 480kg/m3 is considered hard.

Green density is determined at the time the tree is harvested. The recorded values can vary depending on the time of year, weather conditions and the age of the tree when it is harvested.

Dry density is taken after the tree has air-dried and has a moisture content of 12%. Again, this figure can vary depending on the growth conditions and age of the tree.

Janka Hardness Rating

The Janka hardness rating shows how well a type of timber can resist scratching or denting. To determine the rating, an 11.28mm steel ball is forced into a sample piece of timber. Once half of the ball has been driven into the timber, the force required to drive the ball is recorded. The higher the Janka rating, the harder the timber. In Australia, the force is recorded in Kilonewton (kN).

Lyctid Susceptibility of Sapwood

Lyctids are pests that attack the sapwood of hardwood timbers. Sapwood is the outer layer of the timber. All softwood timbers are not susceptible to attack. Legislation governs the sale of timber that is susceptible to lyctids in New South Wales and Queensland. Australian Standards limit the use of luctid susceptible sapwood throughout Australia.

Termite resistance of Heartwood (Above Ground)

The heartwood of some species of timber is naturally resistant to termites. Heartwood refers to the inner part of the wood. There are some species of timber where the heartwood is resistant to termites but must still be treated. This is due to the amount of sapwood they have.

Durability Class – Above Ground & In Ground

Durability refers to the ability of the heartwood to resist insect attack and decay when used in ground. The performance is usually increased when above ground. Durability can vary in timber from the same species and even from the same tree. Because of this, durability ratings are a guide only. Durability ratings are as follows:

Above Ground

• Class 1: Very durable – Over of 40 years above ground
• Class 2: Durable – Between 15 and 40 years above ground
• Class 3: Moderately durable – Between 7 and 15 years above ground
• Class 4: Non-durable – less than 7 years above ground

In Ground

• Class 1: Very durable – Over of 25 years in ground
• Class 2: Durable – Between 15 and 25 years in ground
• Class 3: Moderately durable – Between 5 and 14 years in ground
• Class 4: Non-durable – less than 5 years in ground

Exposure to Marine Borers

There are many different kinds of marine borers. All live in seawater or brackish water (salt water and fresh water mixed together). Marine borers, as their name suggests, bore into and eat wood. Similar to durability, timber species are categorised into classes when referring to their ability to resist marine borers. Each class has a probable resistance expectancy listed in years:

• Class 1: Over 60 years
• Class 2: Between 41 and 60 years
• Class 3: Between 21 and 40 years
• Class 4: Less than 20 years (usually less than 5 years)

Strength Group

The strength of a type of timber refers to its ability to maintain stress without failing. The strength group is determined by identifying three factors:

1. Modulus of rupture: Also known as bend strength, it is the stress in the timber before it breaks in a bend test
2. Modulus of elasticity: Measures the resistance of the timber being deformed when stress is applied to it
3. Maximum crushing strength: Also known as compression strength, this shows how well the timber can withstand a compressive force

The above values are measured in megapascal (MPa). To identify the strength group of each species, 5 samples are tested and the average values collected. There are 7 strength groups for green (unseasoned) timber and 8 for dry (seasoned) timber. The lower the number, the stronger the timber. Green timber is identified with an S and dry is identified with SD.

Joint Group

The joint group is used to identify the bearing strength of the timber. It also shows the shear strength at the joins. There are 6 groups that are separated into green (unseasoned) – J, and dry (seasoned) – JD. J1/JD1 is the highest (strongest) rating and J6/JD6 is the lowest (weakest). Where a joint has two or more different species of timber, the lowest rated joint group should be used.

Radial & Tangential Shrinkage

Shrinkage is the difference in dimensions from when the tree is cut down to when it dries to 12% moisture content. Shrinkage is measured in radial (perpendicular to the growth rings) and tangential (parallel to the growth rings). Shrinkage can vary considerably within each species.

Stress Grade – Seasoned & Unseasoned

Stress grades are used for design purposes. They are only applied to structural timber products. The process of grading is to determine the stress limits that apply to timbers for structural applications. There are 10 F grades – F4, F5, F7, F8, F11, F14, F17, F22, F27, and F34. F4 represents the weakest and F34 represents the strongest timber. Where testing shows that a timber could come under more than one grade, the lower grade will be assigned.

Early Fire Hazard Indices – Ignitability, Spread of Flame & Smoke Development

Building materials, in some building applications, are required to have particular characteristics in the early stages of a fire. This is required by the Building Code of Australia (BCA). There are 3 indexes:

• Ignitability – Rated on a scale of 0 - 20 where 0 is the least likely to ignite
• Spread of flame – Rated on a scale of 0 - 10 where 0 is the slowest to spread flame. If ignitability is rated at 0, the spread of flame will be rated at 0
• Smoke development – rated on a scale of 0 - 10 where 0 develops the least amount of smoke

pH Levels

pH refers to the amount of hydrogen ions in the timber. Where the pH level is rated at 7, it is considered neutral. Anything lower than 7 is considered acidic. Anything higher than 7 is considered alkaline.