Practical advice for heavy-duty concrete fixings
Choosing the right fasteners is essential for strength, safety and efficiency – especially when you’re attaching heavy loads to dense materials like concrete.
But with so many sizes, finishes and features available, it can be difficult to know which option to choose.
That’s why we’ve put together this quick buyer’s guide to help you find the best concrete fasteners for heavy loads based on the needs of your project.
And if you need related products like drill bits, fastening tools, mounting brackets and sealants, you can order them all together using our online shop.
How to read concrete fastener sizes
Concrete fasteners often use short codes to describe their size and finish.
As a reminder:
- M: This shows the bolt’s diameter in millimetres. For example, M10 is 10 mm wide
- x 80: The number after the ‘x’ is the bolt’s length in millimetres. So an M10 x 80 is 10 mm wide and 80 mm long
- A40 stainless steel: A marine-grade stainless steel that resists corrosion in coastal, wet or chemically aggressive environments
- Galvanised: A protective zinc coating applied to the fastener protects against rust, making it ideal for outdoor use
- BZP: This stands for ‘bright zinc plated’, a thinner zinc coating that protects against corrosion in indoor or sheltered conditions
Top 10 best concrete fasteners for heavy loads
1) For heavy-duty structural work
If you need a strong, dependable fixing, the M16 x 150 Concrete Bolt is a solid choice.
Its bright zinc finish resists corrosion, while the hex-flange head delivers secure tightening and reliable load transfer.
Because it’s non-expansion, you can fix close to edges without risking cracks in concrete or blockwork.
That makes it ideal when you want strength and a clean installation in one package.
Ideal uses:
- Securing steel columns to a concrete base
- Fixing heavy-duty racking uprights
- Anchoring machinery baseplates
- Attaching crash barriers in warehouses
- Installing industrial support frames
2) For coastal and corrosive environments
Working in harsh or coastal environments calls for the M10 x 75 A4 Stainless Steel Bolt.
Made from A4 marine-grade stainless steel, it offers outstanding resistance to rust and chemical attack.
And you can install it quickly without stressing or cracking the surrounding substrate.
This bolt is the right option if your project demands long-term performance in aggressive conditions like high-chemical food plants to salt-air seafronts.
Ideal uses:
- Fixing stainless steel balustrades
- Anchoring outdoor signage brackets
- Securing guardrails in food-safe environments
- Mounting external light posts
- Installing swimming pool handrails
3) For deep embedment
Sometimes you need deeper embedment than a standard fixing provides.
At 200 mm long, the M10 x 200 Concrete Bolt lets you achieve a deeper, more secure hold in thick slabs or foundations.
Its zinc plating protects against corrosion indoors, while the self-tapping thread makes installation fast and straightforward.
Use it where strength and depth are equally important.
Ideal uses:
- Anchoring tall steel posts into slabs
- Fixing bollards to deep foundations
- Securing barrier supports in car parks
- Attaching heavy baseplates for equipment
- Installing vertical pipe supports in concrete
4) For versatility across materials
The M12 x 200 Concrete Bolt balances heavy-duty performance with versatility.
It grips firmly in concrete and masonry, and its 200 mm length makes it ideal for thicker materials.
The zinc plating protects against corrosion indoors, while the hex-flange head allows you to achieve reliable torque.
It’s a dependable option whenever you need both strength and adaptability.
Ideal uses:
- Fixing crane rail supports
- Anchoring canopy frames to foundations
- Securing mezzanine floor posts
- Installing steel stanchions
- Mounting switchgear housings onto plinths
5) For smaller fixings
When you’re handling smaller materials, the M6 x 100 Concrete Bolt gives you secure fixing without excess size.
At just 6 mm in diameter, it’s slim enough for repeated applications, but still provides strong anchoring.
The zinc plating also adds protection indoors, and the hex-flange head ensures a neat finish.
Choose it when you want multiple small fixings that are quick to install yet completely reliable.
Ideal uses:
- Mounting electrical trunking
- Fixing steel brackets
- Securing cable trays to walls
- Installing pipe clips in concrete walls
- Attaching small access panels
6) For straightforward installation
Expansion anchors don’t come much more straightforward than the M12 x 150 BZP Throughbolt.
Once torqued, it locks securely into concrete, giving you confidence in heavy-load fixings.
Its bright zinc plating makes it suitable for indoor environments, and the simple drill–insert–torque process saves time on site.
Pick this throughbolt when your project calls for strength, speed and proven reliability.
Ideal uses:
- Anchoring steel beams to pads
- Fixing stair stringers into concrete
- Securing heavy handrail posts
- Installing permanent guard rails
- Attaching heavy equipment to floors
7) For outdoor durability
If your fixings will face harsh weather, the M10 x 80 Galvanised Throughbolt is a safe bet.
Its galvanised coating provides resistance against rust, keeping performance steady in outdoor environments.
And at 80 mm, it’s compact but strong enough for heavy-load applications.
Use it when your project demands durability outdoors without sacrificing anchoring strength.
Ideal uses:
- Fixing outdoor guardrails
- Anchoring street furniture to slabs
- Securing solar panel mounting frames
- Installing external fencing brackets
- Attaching façade support rails
8) For maximum load capacity
In the toughest structural work, the M20 x 300 BZP Throughbolt provides maximum anchoring capacity.
Its large diameter and extended length make it suitable for the heaviest loads.
Once expanded, it locks into concrete securely, and the zinc plating offers long-lasting protection indoors.
Reach for this fixing when your project leaves no room for compromise on strength or safety.
Ideal uses:
- Anchoring structural gantries
- Fixing bridge bearing plates
- Securing industrial machinery bases
- Installing heavy conveyor structures
- Attaching large steel bracing systems
9) For thicker sections
With a length of 180 mm, the M16 x 180 BZP Throughbolt handles thicker sections and stand-off installations with ease.
Its expansion design creates a secure hold in concrete once tightened.
And the zinc plating protects against indoor corrosion.
This is a versatile choice when you need strength but also flexibility in how and where you fix.
Ideal uses:
- Fixing safety barriers
- Anchoring large handrails
- Installing warehouse mezzanine columns
- Securing structural stair towers
- Attaching access ladders to concrete pads
10) For long-term external reliability
In outdoor or coastal projects, stainless steel gives you peace of mind.
The M12 x 115 Stainless Steel Throughbolt resists corrosion in harsh environments, holding firm even when exposed to salt or moisture.
Its expansion design grips concrete securely, making it perfect for safety-critical external fixings.
Choose this fastener when your project demands both high strength and lasting durability.
Ideal uses:
- Anchoring external balcony railings
- Fixing canopy frames outdoors
- Securing marine walkway structures
- Installing stainless guardrails in public areas
- Attaching safety fencing in coastal sites
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With over 35 years’ in the industry, we’re a trusted supplier for construction, engineering and DIY industry clients throughout the UK and Ireland. So you can simplify ordering and receive leading customer service all in one.
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