Anchor Bolts & Steel Screws
Mechanical anchors and stainless screws that hold expansion joint covers, facades and fixtures to concrete — sized, coated and embedded correctly, because a joint cover is only as good as what fastens it.
The Failure Point Nobody Budgets For.
Expansion joint systems let structures accommodate movement from thermal fluctuation, settling and seismic activity. But every cover plate, frame and retainer in that system transfers its load through anchors. Undersized, under-embedded or corroded fixings are how "lifetime" joint covers end up rattling loose in five years.
As manufacturers of Dseal expansion joint covers, we supply the fasteners we would specify for our own installations — for joint covers, facade fixings and general structural work.
Seven Anchor Types, Two Screw Families.
Wedge Anchors
The go-to heavy-duty fixing for cracked-free concrete — expands against the bore under torque.
Sleeve Anchors
Full-length expansion sleeve distributes load — forgiving in brick and block as well as concrete.
Drop-In Anchors
Flush internally threaded sockets for suspended fixings and removable bolted connections.
Hammer Drive Anchors
Fast nail-in fixings for light-duty attachments and framing.
Headed Bolts
Cast-in anchor bolts for planned connections poured with the concrete.
Bent Bar Anchors
J- and L-shaped cast-in bars for base plates and column anchorage.
Plate Anchors
Embedded plate assemblies where loads must spread over a larger bearing area.
Steel Screws
Stainless steel and self-tapping screws for cover plates, frames and sheet fixing.
Material, Coating, Embedment.
| Decision | Options | Guidance |
|---|---|---|
| Material | Carbon steel · Stainless steel | Stainless (ref. ASTM A307, A325) for high-moisture and exterior exposure; carbon steel for dry interiors |
| Coating | Zinc plating · Hot-dip galvanizing · Fluoropolymer / PTFE | Zinc for interiors; HDG for weather exposure; PTFE/fluoropolymer where chemicals attack |
| Embedment depth | Rule of thumb: 10× bolt diameter minimum | A 10 mm bolt wants ≥100 mm embedment — shallow anchors are the classic pull-out failure |
| Geometry | Size & spacing · Edge distance | Respect edge distances and anchor spacing to avoid concrete cone breakout |
| Loads & environment | Static, dynamic, seismic · Wet, chemical, coastal | Match anchor type and coating to load conditions and exposure — not to what is in the van |
Relevant standards referenced for bolt material and strength: ASTM A307, A325 and A36.
Six Steps to a Fixing That Stays Fixed.
- Prepare the substrate — sound, clean concrete, no loose material.
- Drill and clean the holes — dust left in the bore robs capacity.
- Set the anchors to the specified embedment and torque.
- Use epoxy where necessary — chemical anchoring for high loads or poor substrate.
- Secure with steel screws where the design calls for them.
- Protect the expansion joint — never let fixings bridge or restrain the movement gap.
Maintenance: visually inspect at least annually; check corrosion protection, re-tighten where needed and keep fixings clean. Anchors in facades and joint covers work for decades — if someone looks at them occasionally.
Upgrading fixings on an ageing building is a core part of our retrofitting & repairs service.
Anchor Fastener FAQs.
How deep should an anchor bolt be embedded?
A minimum embedment depth of 10 times the bolt diameter is the working rule — so a 12 mm anchor wants at least 120 mm into sound concrete. Load conditions, edge distance and substrate quality can push that requirement deeper.
Which anchor type is best for concrete?
Wedge anchors are the standard heavy-duty choice for sound concrete; sleeve anchors are more forgiving in mixed masonry; drop-in anchors suit suspended and removable fixings. For very high loads or fixing near edges, chemical anchoring with Lokfix or AnchorFix outperforms mechanical expansion.
What coating do I need to stop corrosion?
Zinc plating serves dry interiors; hot-dip galvanizing is the minimum for weather-exposed fixings; fluoropolymer/PTFE coatings or stainless steel (ASTM A307/A325 referenced grades) for chemical and high-moisture environments.
How often should anchors be inspected?
At least annually: a visual check for corrosion and movement, re-tightening where required, and cleaning. On expansion joint covers, also confirm no fixing has come to bridge the movement gap.