When you order a shaft, pin or bushing, the material matters as much as the measurements. The wrong steel can bend under load, wear out fast or rust within months near the coast. The right one lasts for years. This guide explains the materials we use most often, in plain words, so you can tell us what you need, or let us recommend one.
Mild steel (S275 / ST37)
The everyday structural steel. It is easy to cut, weld and machine, and it is the cheapest option.
Good for: brackets, base plates, frames, spacers, gates, burglar bars and parts that carry light loads.
Not good for: shafts that carry real torque, parts that slide or wear, anything that needs to stay hard.
Mild steel rusts, so outdoor parts need primer and paint or galvanising.
Carbon steel C45 / EN8
This is the workhorse for shafts. C45 (European name) and EN8 (British name) are very close, and in practice they are used for the same jobs. It has more carbon than mild steel, which makes it stronger and more resistant to wear.
Good for: drive shafts, pump shafts, axles, pins, couplings, gear blanks and most rotating parts in mining, sugar mills, agriculture and workshops.
Worth knowing: C45 can be hardened where it wears, for example at a bearing seat. It still rusts, so keep it oiled or painted where it is exposed.
If you are not sure what a broken shaft was made of, C45 / EN8 is often the safe replacement for general machinery.
Stainless steel 304
Stainless steel contains chromium, which stops normal rust. 304 is the most common grade.
Good for: food and drink equipment, water systems, parts that are washed often, and anything that must look clean.
Not good for: constant salt spray or chlorine. In those conditions 304 can still pit and stain.
Stainless steel is softer and more expensive than C45, and it is harder to machine, so expect a higher price.
Stainless steel 316
316 adds molybdenum, which gives it much better resistance to salt and chemicals.
Good for: parts near the sea in Maputo, Beira, Nacala and Pemba, boat and port equipment, chemical pumps and anything that sits in salt water.
If a part works within sight of the ocean and you want it to last, 316 is usually worth the extra cost.
Brass
Brass is soft, does not rust and slides well against steel.
Good for: bushings, valve parts, fittings and electrical parts.
Aluminium 6061
Aluminium is about a third of the weight of steel and machines quickly.
Good for: light covers, brackets, spacers and parts where weight matters more than strength.
Nylon and engineering plastics
Nylon (PA6) is light, quiet and slides without grease. It does not rust and it does not conduct electricity.
Good for: wear strips, rollers, light-duty bushings and guides, especially where grease would collect dirt.
How to choose, quickly
Ask three questions:
- What load does it carry? Heavy torque or impact points to C45 / EN8.
- Does it see water, salt or chemicals? Fresh water points to 304. Salt or chemicals point to 316.
- Does weight or noise matter? Then aluminium or nylon.
Tell us and we will advise
You do not have to decide alone. In the quote form or in Part Studio, choose “Not sure: advise me” and tell us where the part works. We recommend a material, explain why, and quote both options when the choice affects the price.