Concrete Expansion Bolts That Hold Tight — M6 to M20 in Multiple Materials
Whether you're mounting a structural bracket, securing heavy shelving, or anchoring machinery to a concrete slab, finding an expansion bolt that won't work loose under load is non-negotiable. These concrete expansion bolts are built for contractors, tradespeople, and serious DIYers who need a reliable mechanical anchor in solid concrete, brick, or stone — without the mess of chemical adhesives.
Each set contains expansion bolts in your chosen material and pack size. Available in 304 Stainless Steel, 316 Stainless Steel, 201 Stainless Steel, White Zinc Plating, and Colour Zinc Plating, with thread diameters from M6 (≈0.24″) to M20 (≈0.79″) and lengths from 50mm (≈2.0″) to 300mm (≈11.8″). Pack sizes range from 1 to 20 pieces depending on the variant selected.
Typical applications include anchoring fence posts and gate hardware to concrete footings, securing wall-mounted shelving and racking systems in warehouses or garages, fastening HVAC brackets and electrical conduit supports to masonry walls, and installing handrails or balustrades on concrete staircases.
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Compatibility: Designed for solid concrete, solid brick, and natural stone. Uses standard metric coarse thread (ISO 68-1) — compatible with metric nuts, washers, and fixtures M6 through M20. Not recommended for hollow block or AAC without engineering review.
✅ Key Features of These Concrete Expansion Bolts
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🏗️Mechanical Expansion Anchor Design — The sleeve expands radially against the drill hole wall as the bolt is tightened, creating a secure friction-and-form-fit hold in solid concrete without adhesive curing time.
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🦾Wide Diameter Range M6–M20 — Covers light-duty M6 anchors for conduit clips up to heavy-duty M20 anchors for structural steel connections, so one product line handles your whole job site.
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🌊316 Stainless Steel Option for Corrosive Environments — The 316 grade adds molybdenum for chloride resistance, making it the go-to choice for coastal construction, pool surrounds, and marine dock installations.
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📏Lengths from 50mm to 300mm (≈2″–11.8″) — Deep embedment options let you anchor through thick fixtures or reach solid substrate beneath surface coatings, giving you the embedment depth needed for higher-load applications.
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⚡Fast Installation with Standard Masonry Drill — Drill, insert, and torque — no mixing, no waiting. Compatible with standard carbide-tipped masonry bits, making these expansion anchor bolts practical for high-volume installation.
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🎨Multiple Finish Options for Every Environment — Choose zinc-plated for cost-effective indoor use, 304 stainless for general outdoor exposure, or 316 stainless for demanding corrosive conditions — all from the same product listing.
📐 Technical Specifications — Concrete Expansion Anchor Bolts
| Product Type |
Concrete Expansion Bolt / Wall Anchor Screw |
| Thread Diameter |
M6, M8, M10, M12, M14, M16, M18, M20 |
| Length Range |
50mm (≈2.0") – 300mm (≈11.8") |
| Thread Standard |
Metric coarse thread, ISO 68-1 |
| Materials Available |
304 Stainless Steel, 316 Stainless Steel, 201 Stainless Steel, White Zinc Plating, Colour Zinc Plating |
| Drive Style |
See variant options |
| Head Style |
See variant options |
| Suitable Base Materials |
Solid concrete, solid brick, natural stone |
| Pack Size |
1, 2, 5, 10, or 20 pieces (varies by variant) |
| Minimum Embedment Depth |
Typically 10× bolt diameter (e.g., M8 → 80mm min.) |
| Corrosion Resistance |
304 SS: good general outdoor; 316 SS: marine/coastal; Zinc: indoor/semi-protected |
| Country of Origin |
Contact us to confirm |
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Note: Always verify the required drill hole diameter, embedment depth, and torque specification for your specific bolt size and base material before installation. For structural or load-bearing applications, consult a qualified engineer.
❓ Frequently Asked Questions
How do I choose the right bolt length for my project?
A general rule: the bolt should embed at least 10× its diameter into the base material. For example, an M8 bolt typically requires at least 80mm (≈3.1") of embedment depth. Add the thickness of the fixture being fastened to get your total bolt length. When in doubt, go one size longer — deeper embedment generally means higher load capacity.
What load can these expansion bolts handle?
Load capacity depends on bolt diameter, embedment depth, concrete strength, and edge/spacing distances. Generally, M6 bolts in solid concrete handle tensile loads of roughly 1–2 kN, while M20 bolts can typically handle 10+ kN under ideal conditions. Always consult a structural engineer for load-critical or life-safety applications.
Can I use these bolts outdoors or in wet environments?
304 stainless steel is suitable for most outdoor and mildly corrosive environments. For coastal, marine, pool surrounds, or highly corrosive settings, 316 stainless steel is generally recommended due to its molybdenum content. Zinc-plated variants are best for dry or semi-protected indoor use and are not recommended for prolonged outdoor exposure.
What thread standard do these expansion bolts use, and are they compatible with standard hardware?
These bolts use standard metric coarse threads (ISO 68-1). M6 through M20 sizing is compatible with standard metric nuts, flat washers, spring washers, and fixtures. Always verify thread pitch with your mating hardware before installation. In most cases, standard metric coarse pitch applies (e.g., M8 × 1.25mm pitch).
What is the difference between 304 and 316 stainless steel for expansion bolts?
304 stainless steel offers good general corrosion resistance and is suitable for most indoor and standard outdoor applications. 316 stainless steel contains molybdenum, which provides superior resistance to chlorides and salt spray — making it the preferred choice for marine, coastal, swimming pool, or chemical plant environments. If you're unsure, 316 is the safer choice for any exposed outdoor installation near water.
What drill bit size should I use for these expansion bolts?
The drill hole diameter should match the bolt's nominal outer diameter. For example, an M8 expansion bolt typically requires an 8mm masonry or hammer drill bit. Always use a carbide-tipped masonry bit and drill to the required embedment depth plus a small clearance for debris. Clean the hole with compressed air or a brush before inserting the bolt.
Are these bolts suitable for hollow block, brick veneer, or AAC (aerated concrete) walls?
Expansion bolts are generally designed for solid base materials such as solid concrete, solid brick, or natural stone. For hollow block, aerated concrete (AAC/Hebel), or cavity walls, a sleeve anchor or chemical anchor is typically more appropriate. Contact us to confirm suitability for your specific substrate before ordering.
🛒 Select your material, size, and pack quantity above, then add to cart — ships from our US warehouse.
