Carbon & alloy steel · EN 10083-3
30CrNiMo8
Overview
30CrNiMo8 is a carbon/alloy engineering steel (EN 10083-3) for shafts, gears, and heat-treated machine parts.
Typical supply: Bars, forgings, plate, tube
Mechanical Properties
Thermal Properties
For temperature derating, open Temperature Properties.
Physical Properties
Typical supply: Bars, forgings, plate, tube
Density typically ~7800–7850 kg/m³. Bar and forging forms dominate machine design.
Applications
- Shafts and axles
- Machine components under fatigue
- Gears and pinions (with heat treatment)
- High-strength fasteners and couplings
Advantages
- Higher strength and hardenability than mild structural steel
- Responds well to quench and temper for tailored properties
- Good fatigue performance when heat-treated correctly
Limitations
- Often needs heat treatment to reach published strengths
- Weldability may require preheat / post-weld heat treatment
- Corrosion resistance similar to carbon steel unless coated
Standards
- EN 10083-3
Equivalent Materials
Electrical Properties
Not published for this grade.
Chemical Composition
Not published for this grade.
Machinability
Machinability index: 40 (AISI 1212 ≈ 100)
Machinability depends on condition; annealed stock machines more easily than QT.
Cost
Relative cost band: high
Low-to-moderate premium over mild steel depending on alloy content.
Corrosion
Class: fair
Protect like carbon steel; oil, plating, or paint for service parts.
- Oil-lubricated machineryfair
- Outdoor uncoatedpoor
For allowance / life screening, open Corrosion Allowance.