Dictionary – Flame and Induction Hardening

Flame & Induction Hardening have a number of distinct advantages.

  • It can be carried out on very large components
  • Very localised areas can be hardened

Flame & Induction Hardening processes require steel alloys with a medium carbon content. The steel can be specified and purchased accordingly or Holts can carburise the component assuming it is within our facility capability and then flame or induction harden.

Excellent control of heating & quenching processes is essential to prevent damage either by distortion or cracking in what can be considered a relatively severe process cycle

Holts are also able to harden one side and then straighten the component. Because the hardened region increases in volume distortion always takes place with asymmetric hardening

Surface hardening through induction or flame heating delivers selective surface hardening precisely where it is required using medium carbon alloy steels. The types of components processed are vast and includes; Gears, Clutches, Cams, Rolls, Shafts, Dies and countless others.

The physical principles underlying the processes of flame and induction hardening are similar, and both restrict the heating and quenching cycle to the required regions on the components surface. With the use of automatic, and semi-automatic precision handling of the machine-tool type, extremely accurately controlled and reproducible hardening cycles are maintained to suit the particular component. As with the more conventional hardening techniques the hardening cycle is normally followed by tempering.

In flame hardening the heat is transmitted to the surface from an external source in the form of an adjacent battery of high temperature flame jets, whilst with induction hardening a high frequency current is passing through an inductor raises the surface temperature of the adjacent work piece by energy losses.

The two techniques are complimentary rather than competitive, with the choice of technique depending on the individual component. Having the widest choice of facilities and equipment available at our Sheffield partners, there are no limitations in determining and undertaking the optimum treatment for customers’ components.