Shaft Machining
Shaft machining turns, mills and grinds shafts to precise diameters, lengths and finishes for rotating assemblies such as motors, pumps, gearboxes and conveyors. Keyways, splines, threads, bearing seats and circlip grooves are machined to the drawing, with heat treatment and grinding where required.
What it is
Shafts are usually turned from bar or forged blanks between centres, then keyways and flats are milled. Bearing and seal diameters are often ground after turning, and hardened after machining where wear resistance is needed.
Straightness and concentricity between diameters are critical for smooth running, so long shafts are supported and checked carefully during and after machining.
Typical applications
- Motor and pump shafts
- Gearbox input and output shafts
- Conveyor and roller shafts
- Spindles and drive shafts
- Agricultural and automotive shafts
Suitable materials
- EN8, EN9 medium carbon steel
- EN19, EN24 alloy steel
- EN36 and 20MnCr5 case-hardening steel
- Stainless steel (410, 431, 304, 316)
Points to consider
- Specify fits for bearing and coupling seats (for example k6 or h6) rather than just a size.
- Provide runout or concentricity requirements between diameters if they matter.
- Choose case hardening or induction hardening for wear zones; state depth and hardness.
- Keyway size normally follows IS 2048 / DIN 6885 for the shaft diameter.
Frequently asked questions
What steel is best for shafts?
EN8 is common for general shafts; EN19 or EN24 for higher strength; case-hardening steels like 20MnCr5 or EN36 where the surface must resist wear.
Do shafts need grinding?
Bearing and seal diameters with tight fits (k6, h6) and fine finish are usually ground after turning, especially after hardening.
Can you repair a worn shaft?
Often yes, by grinding and hard chrome plating or metal spraying to restore the size, which can be cheaper than making a new shaft.