Macalloy 460 Bar System

Engineers all over the world have used Macalloy systems in the most diverse of applications. Among these are bridges, government buildings, stadia, airports, and hotels, to name just a few. The longevity and design again reflect the level of innovation and quality, which have become firm components of Macalloy products.

Macalloy 460 is a hot rolled carbon steel, with excellent mechanical properties. The thread is rolled, rather than cut. This gives rise to the use of smaller diameter bars for a given metric thread, resulting in material cost saving. The carbon Macalloy 460 is also a weldable steel with a maximum carbon equivalent of 0.55%. Arc welding may be carried out using standard techniques and low hydrogen rods.

Macalloy 460
Carbon Bars.

The Macalloy 460 bar has the following mechanical properties:

  • Minimum Yield Stress 460 N/mm2
  • Minimum Breaking Stress 610 N/mm2
  • Minimum Elongation 19%
  • Minimum charpy Impact Value 27J @-20°C
  • Nominal Young’s Modulus 205 kN/mm2

The standard diameter range for this system is from M10 to M100. In addition, other diameters can be supplied but are subject to longer lead times. Tendons up to and including M16 diameters can be supplied in lengths of 6m. For larger diameter, lengths of up to 11.95m are available. Greater lengths are possible using couplers and turnbuckles. These fittings are designed to take the full load of the bar.

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

Special turnbuckles, with a greater adjustment are available on request. Contact a Macalloy agent today to or use our live chat option to discuss your requirements.


Threads are rolled on to the bar and are therefore more resistant to fatigue. Testing a range of diameters has been carried out over 2 million cycles, the results of which are available from the Macalloy technical department.

Corrosion Protection

Macalloy tendons can be supplied in plain carbon steel, primed, or hot 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 at the bar can then be enhanced.

Macalloy offers any kind of paint finish (primer, paint or fire protection) for hot dip galvanised, or self colour tendons. These finishes will be sourced from certified suppliers.

European Approval

The Macalloy 460 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.