Serrated Expansion Anchors for Concrete & Hollow Walls — Reliable Fastening in M5 to M10
When a standard screw won't hold in concrete, brick, or hollow masonry, you need an anchor that actually grips. Whether you're a contractor hanging electrical conduit, a facilities manager mounting shelving to a block wall, or a serious DIYer securing a TV bracket to a concrete ceiling, the wrong fastener means callbacks, failures, and safety risks. These serrated expansion anchors are engineered to expand and lock into the substrate as you tighten — no epoxy, no guesswork.
Each set contains serrated expansion anchors in your chosen size and pack quantity. Available in M5×30mm (≈3/16" × 1-3/16"), M6×32mm (≈1/4" × 1-1/4"), M8×38mm (≈5/16" × 1-1/2"), M8×60mm (≈5/16" × 2-3/8"), and M10×60mm (≈3/8" × 2-3/8"). Finish options include blue-zinc plated carbon steel, coloured-zinc carbon steel, and 304 stainless steel for corrosion-sensitive environments. Drive styles are Phillips-Head (M5, M6) and Hexagon Head (M8, M10). Pack sizes range from 1 to 50 pieces; Single Tube options are available for trade quantities.
Typical applications include mounting electrical junction boxes to concrete walls, securing pipe hangers and conduit clips to masonry ceilings, anchoring shelf brackets and cabinet rails to hollow block walls, and fastening structural brackets in light commercial construction — all scenarios where a reliable concrete anchor bolt for hollow walls is essential.
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Compatibility: Designed for standard metric threads — M5, M6, M8, M10. Compatible with metric bolts and machine screws. Not designed for UNC/UNF inch-standard fasteners. Confirm hole diameter and substrate type before ordering.
✅ Key Features of These Serrated Expansion Anchors
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🔩Serrated Sleeve Design — The knurled outer sleeve bites into the drilled hole wall as the bolt is tightened, creating a mechanical lock that resists pull-out in concrete and masonry without adhesive.
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🛡️Multiple Finish Options — Blue-zinc and coloured-zinc carbon steel for dry indoor use; 304 stainless steel variants for damp or outdoor environments where corrosion resistance is needed.
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🔧Two Drive Styles — Phillips-Head for M5 and M6 sizes suits standard drill drivers; Hexagon Head for M8 and M10 allows wrench or socket installation for higher-torque concrete anchor bolt applications.
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📐Full Metric Size Range — M5 through M10 covers the most common hollow wall anchor sizes used in residential and light commercial construction, from lightweight fixture mounting to structural bracket fastening.
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📦Flexible Pack Quantities — Order as few as 1 or as many as 50 pieces per variant, plus Single Tube trade packs — so you buy exactly what the job requires without overstocking.
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⚙️Dual-Length Options for M8 — M8 is available in both 38mm (≈1-1/2") and 60mm (≈2-3/8") lengths, giving you the right embedment depth for thin-wall block or thicker solid concrete applications.
📐 Technical Specifications — Serrated Expansion Anchor Bolts
| Product Type |
Serrated Expansion Anchor (Concrete / Hollow Wall) |
| Thread Sizes Available |
M5, M6, M8, M10 |
| Lengths Available |
30mm (≈1-3/16"), 32mm (≈1-1/4"), 38mm (≈1-1/2"), 60mm (≈2-3/8") |
| Drive Style |
Phillips-Head (M5, M6) / Hexagon Head (M8, M10) |
| Finish Options |
Blue-Zinc Plated, Coloured-Zinc Plated |
| Material Options |
Carbon Steel (Zinc-plated) / 304 Stainless Steel |
| Thread Standard |
Metric (ISO) |
| Suitable Substrates |
Concrete, brick, block, hollow masonry wall |
| Pack Sizes |
1, 2, 5, 10, 20, 50 pcs; Single Tube trade packs |
| Installation Method |
Drill, insert, tighten — mechanical expansion |
| Corrosion Rating (304 SS) |
Suitable for damp / outdoor environments |
| Corrosion Rating (Zinc) |
Suitable for dry indoor environments |
| Country of Origin |
See variant options |
| Certifications |
Contact us to confirm |
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Note: Always verify anchor size, substrate type, and required embedment depth before installation. For load-critical or structural applications, consult a licensed engineer.
❓ Frequently Asked Questions
How do I choose the right size expansion anchor for my project?
Match the anchor diameter to your bolt or screw size. M5 (≈3/16") suits lighter fixtures and conduit clips; M6 (≈1/4") works for medium loads like shelf brackets; M8–M10 (≈5/16"–3/8") handle heavier structural applications. Length should generally embed at least 3× the anchor diameter into solid substrate. Our range covers 30mm (≈1-3/16") to 60mm (≈2-3/8") to suit most common wall thicknesses.
What load can these serrated expansion anchors hold?
Load capacity depends on anchor size, substrate density, and installation depth. Generally, M5 anchors are suited to lighter loads (typically up to a few hundred pounds in solid concrete), while M8–M10 anchors support heavier structural loads. Hollow masonry walls typically have lower pull-out values than solid concrete. For load-critical applications, always consult a structural engineer and refer to published anchor load tables.
Can I use these anchors outdoors or in wet areas?
The 304 stainless steel variants are generally suitable for outdoor and damp environments, offering meaningful corrosion resistance for exposed installations such as exterior wall brackets or covered patio fixtures. The blue-zinc and coloured-zinc carbon steel versions are best reserved for dry indoor use. For coastal, marine, or highly corrosive environments, 316 stainless steel is typically recommended.
Are these anchors compatible with standard metric bolts and screws?
Yes. These expansion anchors follow standard ISO metric thread sizing — M5, M6, M8, M10 — and are compatible with standard metric bolts and machine screws. They are not designed for UNC or UNF inch-standard fasteners. If you are working with inch-standard hardware, please contact us to confirm compatibility before ordering.
What wall or substrate types work with these anchors?
These serrated expansion anchors are designed for concrete, brick, block, and hollow masonry walls. The serrated sleeve mechanically expands and grips the substrate as the bolt is tightened. Performance in hollow walls depends on wall thickness and material density. In very thin or fragile hollow walls, a toggle bolt or cavity anchor may be more appropriate — confirm suitability for your specific substrate before installation.
What is the difference between Phillips-Head and Hexagon Head variants?
Phillips-Head variants (available in M5 and M6) are driven with a standard #2 or #3 Phillips screwdriver or power bit — convenient for lighter-duty installs where a drill driver is the primary tool. Hexagon Head variants (M8 and M10) require a wrench or socket and are suited for higher-torque applications where a more secure, slip-resistant drive is needed during anchor expansion.
What does 'Single Tubes' mean in the size options?
'Single Tubes' refers to anchors packaged in individual tubes — each tube contains a set quantity of one anchor size. This format is designed for contractors and trade buyers who need consistent single-size quantities for repetitive installations, without mixed-size packs. It simplifies job-site inventory and reduces waste.
How do I install a serrated expansion anchor correctly?
1. Drill a clean hole matching the anchor's nominal diameter and at least the anchor's length in depth. 2. Clear dust from the hole. 3. Insert the anchor flush with or slightly below the surface. 4. Insert the bolt or screw and tighten progressively — the serrated sleeve expands outward and grips the hole wall. 5. Do not overtighten, as excessive torque can crack brittle substrates like aerated concrete block.
🛒 Select your size and pack quantity above, then add to cart — ships from our US warehouse.
