Every heavy fixing into masonry comes down to the same choice: an anchor that expands to grip the hole, or resin that glues a threaded stud into it. Mechanical anchors — through bolts, shield anchors, sleeve anchors — are faster and cheaper. Resin systems are slower and costlier but carry the highest loads, work in the widest range of base materials, and hold approvals the mechanicals can't match.

Here's how to choose between them without over- or under-specifying.

Quick reference — resin vs mechanical at a glance

 

Mechanical (through bolt, shield, sleeve)

Resin (Fischer injection & capsules)

How it holds

Expansion pressure grips the hole wall

Resin bonds a threaded stud or rebar into the hole

Base materials

Concrete; shield/sleeve anchors also brick

Concrete, masonry, brick, block — plus rebar connections

Load capacity

Good; certified on through bolts (ETA Option 7, non-cracked concrete)

Highest — system approvals for non-cracked concrete, masonry and rebar

Speed

Fastest — drill and set, load straight away

Slower — inject/capsule, cure time before loading

Edge & spacing

Expansion stress needs edge distance

No expansion stress — fix closer to edges and faces

Stud choice

Fixed to the anchor itself

Any threaded stud — zinc, galvanised or A4 stainless

Cost per fix

Lower

Higher (resin + studs + dispensing nozzle)

The mechanical family — what's in the drawer

Three anchor types do most of the trade's mechanical work:

  • Through bolts (M6–M24): the torque-controlled expansion anchor and the go-to for concrete. CE approved with an ETA Option 7 assessment for non-cracked concrete — when a drawing specifies a certified expansion anchor, this is it. Concrete only, though: not brick or block.

  • Shield anchors (M6–M16, loose bolt): a three-way expansion shield whose thick expanders tolerate oversize holes drilled in weaker materials — which is exactly why they're the workhorse in brickwork, where hole tolerance is never perfect.

  • Sleeve anchors: the general-purpose all-rounder for brick, block and concrete, in hex and socket-head styles.

The shared trait: they all push outward as they set. That's where their speed and their limitations both come from — instant grip on one hand, edge-distance and substrate-strength demands on the other.

Where resin changes the game

A resin system — Fischer injection resin or resin capsules — bonds a threaded stud into a drilled hole. The resin fills the hole completely, keys into the base material, and cures into a solid mass around the thread. No expansion means:

  • Fixings close to edges and closer together. No outward pressure, so no splitting risk near corners, thin walls or slab edges.

  • The highest loads. The bonded length is your dial to turn — deeper hole, more resin, more load. It's why resin owns the structural and rebar work.

  • Any stud you like. Because the anchor is a separate threaded stud, you choose the material for the environment: zinc plated for dry internal work, galvanised for general external, A4 stainless for coastal and chemical-exposure jobs.

  • Approvals that cover more ground. Our Fischer systems carry approvals for non-cracked concrete, masonry and rebar connections, with CE marking — the mechanicals only tick the concrete box.

  • Weak and awkward substrates. Hollow and airy materials like aircrete have a dedicated Fischer system, and resin in a sleeved hole handles hollow block that would defeat an expansion anchor.

The trade-offs to be honest about

Resin isn't automatically "better" — it's better engineering for harder jobs, at a cost:

  • Cure time. A mechanical anchor takes load the moment you torque it. Resin needs its cure time, which depends on the product and the temperature — cold weather slows it down, which is exactly why we stock a winter-grade resin (Fischer FIS VW Plus 360 S) for cold-site work alongside the standard vinylesters (FIS V Plus 360 S, FIS VL 300 T and VL 410 C).

  • Hole preparation is not optional. Brush and blow the hole out. Dust left in the hole is the single biggest cause of resin fixings underperforming, and it costs thirty seconds per hole.

  • Kit and consumables. You'll want an applicator gun and a fresh mixing nozzle per session. Capsules trade the gun for per-hole cost, and suit lower volumes.

  • Cost per fixing. Resin plus stud plus nozzle beats a through bolt on price by a wide margin — in the wrong direction. Use mechanicals where they're adequate; spend the resin money where the load, substrate or approval demands it.

Choosing in ten seconds

  1. Concrete, moderate load, speed matters? Through bolt.

  2. Brickwork and masonry, everyday loads? Shield or sleeve anchor.

  3. High structural loads, close to an edge, hollow block, aircrete, rebar, or a spec that calls for certified performance? Resin.

  4. Fixing near the coast or in a corrosive environment? Resin with an A4 stainless stud.

One rule that covers both families: whatever you use, the hole diameter and depth come from the manufacturer's data for that exact product — and the dust comes out before anything goes in.

Building something serious? Browse the Fischer resin range — injection resins, capsules, studs and guns — or shop shield anchors, sleeve anchors and through bolts. Trade prices, stock in Crewe and fast UK delivery. Questions on a specific fixing? Call the team on 01270 252 326.

Further reading: Resin fixings explained — popular styles · What is a Thunderbolt anchor? · Product Information: Through Bolts · Product Information: Sleeve Anchors