BS 4360 Grade 43A / SABS 1431 Grade 300VA

BS4360 Grade 43A is a lower strength structural steel and is supplied in normalised conditions and are silicon killed in order to improve the steel cleaniness, and to ensure fine grain structures.


Welding procedures are dependant on the Carbon content as reflected on each Test Certificate.


These steels can be formed at room temperatures provided adequate power is available and the correct process is employed. A working 20% uprating on mild steel requirements is recommended making use of the following inside radius forming tolerances.

  • 2 2-1 for right angle forming
  • 3-1 for forming parallel

A trial run may be necessary in order to determine the springback allowance for close tolerance work.


Equipment should be regulated to allow 20% increase in strength as opposed to that of conventional mild steels. High-speed steel or Carbide tooling is recommended, speeds should be reduced by approximately 20% and a goodlubricant/coolant will increase tool life. When punching or shearing, a clearance of approximately 3% should be allowed for the shear angle.


Conventional Flame cutting equipment can be used without resorting to pre- or post-heating operations.


  • Mine fans
  • Earthmoving buckets
  • Trailers and large road vehicles
  • Drill rigs
  • Cranes
  • Excavators
  • Underground mining equipment
  • Bridges
  • Other high strength components requiring superior toughness.