Concrete Screws Explained: How to Choose the Right Masonry Anchor for Concrete, Brick & Stone
When you’re fixing into concrete, brick, or stone, the fastener you choose makes a big difference to strength, reliability, and long-term performance. At SD Aluminium, we stock a dedicated range of concrete screws—also commonly called a concrete screw, masonry screw, or masonry anchor—designed specifically for masonry substrates, so you can achieve a secure hold for everything from outdoor fixtures to structural brackets.
In this article, we’ll explain what concrete screws are, why hot zinc plated (hot-dip galvanised) finishes matter, and how to choose the right diameter and length—using our Hex Flange Head Masonry Anchor – Hot Zinc Plated Concrete Screw range as a practical reference.
What is a concrete screw (masonry anchor)?
A concrete screw—often listed under masonry anchors—is a high-strength steel fastener engineered to anchor into masonry surfaces such as concrete, brick, and stone. These fasteners are made for “real-world” job sites: quick to install, strong under load, and suitable for projects where a standard screw simply won’t perform on masonry.
Unlike general screws that are designed for timber or metal sheet, masonry anchors are purpose-built for the density and hardness of masonry materials.
Why hot zinc plated (hot-dip galvanised) matters
In many New Zealand environments—especially outdoor installs or humid areas—corrosion resistance is not optional. A fastener may look fine on day one, but rust can weaken performance and create maintenance issues over time.
Our hot zinc plated / hot-dip galvanised concrete screws are designed to provide enhanced corrosion protection, making them a smart choice for:
- Outdoor fixtures exposed to rain and moisture
- Fixings around coastal or damp areas
- Long-term installations where durability matters
If your project involves fences, handrails, exterior brackets, or any semi-exposed mounting, this coating helps support a longer service life and a more reliable hold.
The benefit of a hex flange head design
Our masonry anchor range uses a hex flange head, a practical design choice for secure tightening and stable clamping. In real terms, it helps with:
- Confident tightening with common tools
- A secure connection when fixing brackets, plates, and frames
- Better stability for heavier-duty installations
For many trade and commercial applications, a hex flange head is simply easier to work with—and more consistent to tighten properly—especially when you’re installing multiple fixings.
Common applications for concrete screws
Concrete screws are used across residential, renovation, and commercial environments. Our hot zinc plated masonry anchors are commonly used for:
- Structural and framing anchoring (where you need a dependable masonry fixing)
- Outdoor fixtures such as fences, handrails, and exterior brackets
- Building and renovation work including mounts, supports, and fixings into brick/concrete
- DIY mounting on masonry walls (where strength and reliability are needed)
- Industrial and commercial installs requiring secure long-term fastening
If the job involves masonry and the consequences of a loose fixing are serious, a dedicated masonry anchor is the right direction.
How to choose the right size: diameter and length
Concrete screws are not one-size-fits-all. The “best” option depends on what you’re fixing, the load, and the substrate quality.
Our masonry anchor range provides multiple options including:
- Thread diameters: M6, M8, M10, M12
- Lengths: 60mm, 75mm, 100mm, 140mm, 150mm, 200mm
Here’s a simple way to choose:
1) Start with the job type and load
Heavier fixtures and higher load requirements typically call for larger diameters (often M10 or M12), while lighter fixtures may suit smaller options (such as M6 or M8).
2) Consider the thickness of the item being fixed
Your fixing needs to pass through the bracket/plate/timber and still achieve sufficient anchoring depth in the masonry. Longer lengths are generally used when the fixture is thicker or when deeper anchoring is required.
3) Check the substrate condition
Solid concrete behaves differently from older brick or softer block. If you’re working with aged or variable masonry, selecting an appropriate diameter and ensuring correct installation becomes even more important.
A common “heavy-duty” reference point is M12 x 100mm, often chosen where extra strength and confidence are needed for demanding installations.
Don’t confuse concrete screws with general screw types
Because the word “screw” covers many products, it’s easy to accidentally select something designed for timber or metal sheet when your job is masonry.
As a rule of thumb:
- If it’s labelled Masonry Anchor / Concrete Screw, it’s intended for concrete, brick, and stone.
- If it’s labelled Self Drilling or Self Tapping, it’s typically designed for metal sheet or general fastening—not for anchoring into concrete (unless explicitly stated as masonry-compatible).
If you’re shopping within a general fasteners category, always check that the product is clearly a masonry anchor when your substrate is concrete or brick.
Final takeaway: a reliable fixing solution for masonry work
If your project involves anchoring into concrete, brick, or stone, a dedicated concrete screw / masonry anchor is one of the most reliable choices. Our hot zinc plated, hex flange head masonry anchors are designed to deliver strong, secure fastening with better corrosion resistance—ideal for both indoor and outdoor installations.
