Induction Hardening in Lahore
Lahore Casting induction hardens on Mominpura Road, Lahore, on parts cast here and on parts brought in. A coil heats the surface above transformation temperature in seconds and a quench locks it as martensite, giving a hard wearing skin over a core that was never heated and stays tough. It only works if the steel has the carbon to harden - roughly 0.35% and up - so tell us the grade first.
Why harden only the surface
A shaft that is hard all the way through is a shaft that snaps. Wear happens at the surface; load is carried by the core. Induction hardening separates the two: the coil puts heat only where the wear is, the quench fixes it there, and the core is left exactly as it was - tough, and able to bend rather than break.
Because the heat goes in locally and fast, distortion is small and local too. A part can often be hardened after rough machining and still hold shape, which is not true of a through-furnace treatment.
The grade decides everything
No process can harden steel that has no carbon in it. Below about 0.35% carbon there is not enough to form martensite and the part comes out the same as it went in. This is the single most common reason an induction hardening job fails, and it is decided before the part is ever made.
Medium-carbon and alloy steels respond well. Mild steel does not - if a mild steel part needs a hard surface, it needs carburising, or it needs to be made from something else. Cast irons can be induction hardened but behave differently and should be discussed case by case.
What to tell us, and why each one matters
The grade decides whether it can be done at all. Which surfaces need to be hard decides the coil. The hardness you want and the depth you want it to reach decide the power and the dwell - and they trade against each other, so the honest answer is sometimes that you can have one or the other.
If the part is already ground to size, say so before it is hardened rather than after: parts grow and move slightly, and the allowance has to exist beforehand.
What it is used for
- Shafts, spindles and axles that run in a bearing or a bush
- Gear teeth and sprockets
- Cam lobes and eccentrics
- Pins, rollers and guide rails
- Liners and wear faces on medium-carbon or alloy steel
- Any surface that wears while the part underneath must stay tough
Not the right process for: Mild and low-carbon steel, which has too little carbon to harden; parts already finish-ground with no allowance left; and thin sections that will crack rather than case.
What to tell us when you ask
- The material grade - this decides whether it can be hardened at all
- Which surfaces or faces must be hard, marked on a drawing or the part
- The hardness you want, in HRC
- How deep the hard case must go
- Whether the part is finish-machined, and what allowance is left
- Quantity, and whether this repeats
Which alloys take an induction hardened surface
- Alloy Steel — AISI 4140, 4340, 8620
- SG Iron (Ductile Iron) — 400/18, 500/7, 600/3
- Grey Cast Iron — FG200, FG260, FG300
- Carbon Steel — AISI 1045, 1050
- Mild Steel — AISI 1020, 1025
Ask about a part
Send a photo, a drawing, or just a description. Induction Hardening is offered on parts cast here and on parts made anywhere else.
Other services
- Sand Blasting — Abrasive driven at the surface under compressed air, stripping moulding sand, mill scale, rust and old paint and leaving a uniform matte finish that primer and paint will hold.
- Everything else done in-house — casting, melting, heat treatment, machining and testing.