Macalloy 520 Bar System

The Macalloy 520 follows tradition and offers an alternative bar system with the same geometry, design and technology as the 460 system. The fittings are designed to take the increased capacity of the system, which is available in diameters M10 to M100 in carbon steel

Macalloy 520
Carbon System.

The Macalloy 520 bar has the following mechanical properties:

  • Minimum Yield Stress 520 N/mm2
  • Minimum Breaking Stress 660 N/mm2
  • Minimum Elongation 19%
  • Minimum charpy Impact Value 27J @-20°C
  • Nominal Young’s Modulus 205 kN/mm2

Adjustments within each fork or spade are:

  • M10 to M56: +/- 1/2 thread diameter
  • M64 to M100: +/-25mm

Turnbuckles give additional adjustments of:

  • M10 to M24: +/-25mm
  • M30 to M100: +/-50mm

In addition, special turnbuckles, with a higher adjustment, are available on request.

Corrosion Protection

Macalloy tendons can be supplied in plain carbon steel, primed, or dip galvanised finish. If requested at the time of order, hot dip galvanising can be applied to tendons after the threading process. The threads are then brushed to remove any excess zinc.

Length permitting, galvanised bars are delivered pre-assembled. This procedure ensures that threads are 100% operational. Connected bars, greater than 12m, are delivered part assembled. Please note that hot dip galvanising is not comparable with a paint finish. The visual appearance of forks and spades may differ in appearance from that of the bar, by virtue of the different material composition.


For architectural purposes, it is recommended a painted finish is applied to the galvanising. The corrosion resistance of the bar can then be enhanced.

European Approval

The Macalloy 520 system has European CE approval under the ETA 21/0053 for all standard diameters from M10 and M100. When specifying, always ask for CE approved systems.

Contact a Macalloy agent today to discuss all things tension rods and architectural structure bars.

Our supply chain continues to expand via an international network of Macalloy agents and distributors, ensuring continued growth in the global market.