Scaffold Fittings

We stock a comprehensive range of scaffold fittings, clamps, and couplers for connecting 48.3mm scaffold tubes, including double, swivel, and single couplers, sleeve couplers, joint pins, and specialist fittings.

These couplers are designed for use in tube-and-fitting scaffolding with our galvanised steel scaffold poles to form secure scaffold structures. For a lighter alternative, we also supply 48.3mm aluminium scaffold tubes suitable for non-load-bearing applications.

Why Choose Our Scaffold Fittings?

  • Safety & Compliance: Manufactured to meet or exceed BS EN 74-1 (for couplers) and BS 1139 standards, with load-bearing capacities tested for slip resistance and failure loads.
  • Quality Options: Available in pressed-steel (cost-effective) and drop-forged (higher-strength) variants.
  • Versatility: Suitable for traditional scaffolding, temporary structures, edge protection, and specialist fixes like girder beams or board retention.
  • Durability: Zinc-plated or galvanised finish protects against rust, ideal for repeated outdoor use.

Common Types of Scaffold Fittings & Their Uses

Here’s a detailed overview of the most popular scaffold fittings we supply:

Fitting Type

Alternative Names

Primary Use

Load-Bearing?

Typical Standard

Double Coupler (Right-Angle)

Fixed Coupler, 90° Coupler

Connects tubes at right angles (e.g., ledgers to standards)

Yes

BS EN 74-1 Class B

Swivel Coupler

Rotating Coupler

Connects tubes at any angle (ideal for diagonal bracing)

Yes

BS EN 74-1 Class A/B

Single Coupler (Putlog)

Wrapover, Half Coupler

Secures putlogs/transoms to ledgers; fixes toeboards or stop-ends

No

BS 1139-2.2

Sleeve Coupler

External Joint Coupler

Joins two tubes end-to-end externally

Yes

BS EN 74-1 Class B

Joint Pin

Internal Spigot, Expanding Pin

Joins two tubes end-to-end internally (bending-resistant)

Limited

BS EN 74-1

Gravlock/Girder Beam Clamp

Beam Coupler

Attaches scaffold tubes to steel beams/flanges (used in pairs)

Yes

Manufacturer-tested

Board Retaining Clamp

BRC, Toeboard Coupler

Secures scaffold boards to prevent uplift or displacement

No

BS 1139

Tredda Plate

Scaffold Board Support Plate

Provides additional support under scaffold legs/uprights

N/A

General compliance

Scaffold fitting frequently asked questions

A scaffold fitting, also known as a scaffold coupler or clamp, is a crucial component in scaffolding construction; it connects the tubes to create a working platform that allows users to access elevated areas. 

In the UK, key standards are BS EN 74-1 for couplers (Class A or B for strength) and BS 1139 for putlog/single couplers. Always check markings on the fitting. 

Pressed steel is lighter and more affordable for general use; drop-forged offers superior strength for heavy-duty applications.

Scaffold fittings and clamps are essential components in a variety of construction and related applications. Their versatility allows them to be used across a broad spectrum of projects, including:

General construction: Scaffold clamps are essential for creating safe, efficient working platforms for a wide range of construction tasks, including bricklaying, painting, rendering, and other necessary building activities.

Temporary works support: They play a critical role in providing support for temporary structures, including formwork for concrete pouring, falsework during construction, and other temporary works required on site.

Event staging: Scaffold fittings are commonly used in the entertainment industry to construct temporary stages, rigging, platforms, seating, and other structures for concerts, festivals, and other events.

Maintenance and repair: These clamps provide crucial access for inspection, maintenance, and repair of existing structures such as buildings, bridges, and other infrastructure, ensuring safe and efficient operations. 

Fittings offer a range of significant advantages, making them indispensable in construction and maintenance:

Versatility: Their ability to connect diverse scaffolding components enables the creation of highly adaptable scaffold structures that accommodate a wide range of project needs.

Strength: Manufactured from robust materials such as steel, these clamps ensure the stability and safety of scaffolding, even under challenging conditions.

Durability: Galvanisation protects the clamps from corrosion, significantly extending their lifespan and ensuring long-term reliability.

Compliance: Adherence to rigorous industry standards and regulations, such as EN 74 BS 1139, ensures that any scaffolding constructed with these clamps meets all necessary safety requirements.

Ease of use: Designed for quick and secure connections, scaffold clamps simplify and expedite the assembly and disassembly of scaffolding structures, saving valuable time and effort.

Enhanced safety: By providing secure, reliable connections, these clamps significantly improve scaffolding safety, creating a stable, safe working platform for personnel. 

We also offer a range of non-standard scaffold fittings for specific project needs:

  • Putlog Head Adaptors – Convert standard tubes into putlogs for brickwork support.
  • Hoarding Couplers – Secure hoarding panels to scaffolding.
  • Prop to Tube Couplers (Double/Swivel) – Connect acrow props to scaffold tubes.
  • Roofing Clamps – Fix temporary corrugated roofing sheets.
  • Oyster Couplers – Specialist angled connections. 

A typical scaffold fitting is designed to withstand a working load of approximately 6.25 kN (kilonewtons) before it starts to slip; this is roughly equivalent to 1,400 pounds of force. However, it’s important to note that this is an approximation, and the actual load capacity may vary depending on the clamp’s design and manufacturer. Always refer to the manufacturer’s specifications to determine the exact load capacity for a particular fitting. 

Scaffold fittings, such as double (right-angle), swivel, sleeve, and putlog couplers, are critical for creating secure connections in tube-and-fitting scaffolding systems. Proper tightening ensures the structure’s stability, prevents slippage, and complies with UK safety standards, such as BS EN 74-1 and NASC TG20:21.

Under-tightening can lead to joint failure, while over-tightening may damage the bolt, nut, or coupler. Always inspect fittings for damage, corrosion, or wear before use.

Recommended Tightening Torque

Most load-bearing couplers (e.g., double and swivel) are tested to achieve their rated slip resistance at a specific torque.

Coupler Type

Recommended Torque

Notes

Double (Right-Angle)

50–54 Nm

Common value; achieves ~6.25 kN slip resistance (Class B).

Swivel

50–54 Nm

Similar to double; ensures resistance to tension/compression.

Sleeve/Joint Pin

40–50 Nm

Lower for internal joints; avoid over-tightening to prevent distortion.

Putlog (Single)

30–40 Nm

Non-load-bearing in some uses; lower torque is sufficient.

Girder/Beam Clamp

Manufacturer-specific (often 50–60 Nm)

Use in pairs; do not excessively over-tighten.

These values align with BS EN 74-1 testing and manufacturer recommendations. Use a calibrated torque wrench for precision on critical structures.

Tools for Tightening

  • Standard Scaffold Spanner/Podger Spanner → Most common; 19/21mm or 21/23mm bi-hex for manual tightening.
  • Ratchet Podger Spanner → For faster work; reversible for efficiency.
  • Torque Wrench → Essential for accurate torque on professional/complex scaffolds.
  • Avoid makeshift tools (e.g., hammers) as they can damage components.

Step-by-Step Tightening Process

  1. Prepare the Tubes and Coupler – Clean tubes and coupler jaws to remove dirt, grease, or rust. Ensure tubes are properly aligned (e.g., at 90° for double couplers).
  2. Position the Coupler – Place over the tubes. For right-angle/swivel: Swing the eye bolt up, seat the horizontal tube, then close.
  3. Hand-Tighten Initially – Finger-tighten the nut to secure the position.
  4. Final Tightening – Use a podger spanner or torque wrench to tighten to the recommended torque. Tighten evenly; check for no movement.
  5. Check the Joint – Push/pull to confirm no slip. Re-tighten if needed.
  6. Regular Inspections – Check tightness weekly or after adverse weather/loading (per HSE and TG20:21).

Best Practices & Safety Tips

  • Follow NASC TG20:21 for overall scaffold design and erection.
  • Only competent, trained persons (e.g., CISRS-qualified) should erect/alter scaffolds.
  • Lubricate bolts lightly if storing for long periods to prevent seizing.
  • Replace any damaged fittings immediately.
  • For DIY/non-professional use: Err on the tighter side but avoid over-torquing; consult professionals for load-bearing structures.

 

If in doubt, contact a qualified scaffolder or supplier for advice. Safety is paramount – incorrect tightening can lead to serious accidents.

 

Yes, they are designed for standard 48.3mm outer diameter scaffolding tubes.

In the UK, scaffold fittings (couplers/clamps) compliant with BS EN 74-1 and BS 1139 standards use a consistent bolt and nut size for compatibility across double, swivel, putlog, and most other couplers. These are typically T-bolts (hammer-head design) with a captive head that slots into the coupler body.

Key Dimensions Summary

Component

Standard Size

Details/Notes

Bolt Thread

½ inch BSW (British Standard Whitworth) or equivalent to ~M12

Most common in British-style fittings; high-tensile (often Grade 8.8).

Bolt Overall Length

80–85 mm (common replacements up to 90 mm)

Thread length ~50–55 mm; T-head width ~24–26 mm.

Nut Size

21 mm Across Flats (AF) hex nut

Industry standard; some sources list 20.5–21 mm. Fits 7/16-inch scaffold spanners.

Washer

Included in sets

Flat washer for even load distribution.

These sizes ensure secure tightening (typically 50–54 Nm torque for load-bearing couplers) and compatibility with standard 48.3 mm scaffold tubes.

Variations by Coupler Type/Region

While UK/British-type fittings stick to the above, international variants differ:

Type/Region

Bolt Thread

Nut Size (AF)

Notes

British (UK/EN 74)

½” BSW / ~M12

21 mm

Most common in the UK: lighter couplers.

German

M14

22 mm (flange)

Heavier-duty; quick-thread options.

American

M14

22 mm (flange)

Often, I-bolt style.

Australian

½”

23 mm (flange)

No washer needed.

Always use replacement bolts/nuts marked for scaffold use to maintain compliance and safety. Damaged or mismatched components can compromise load ratings.

For professional scaffolding, consult NASC TG20:21 guidelines and inspect fittings regularly. If replacing parts, source from reputable UK suppliers to ensure EN 74 compliance.

 

The integrity of scaffold fittings is crucial for safety, and regular inspections are necessary to identify any signs of damage or looseness. Here is a general guideline for how often these inspections should occur:

Prior to each use of a scaffold structure, a brief visual inspection should be performed to identify any readily apparent damage or loose connections.

A thorough inspection for damage, corrosion, and tight connections is required weekly.

In the event of any incident that may have compromised the scaffold’s integrity, such as a heavy impact or exposure to extreme weather conditions, the fittings must be inspected without delay.

What to look for during inspections:

Damage: Look for cracks, dents, or corrosion on the clamps.

Loose connections:  Double-check that all nuts and bolts are securely fastened.

Correct fit: Confirm that the clamps being used are the appropriate size and type for the scaffold tubes they are intended to connect.

Proper installation: Ensure the scaffold fittings are installed in strict accordance with the manufacturer’s instructions.