C630 (NAB)
A nickel aluminum bronze (NAB)
Typical values for the temper in the title
C630 contains about 10% aluminum, about 5% nickel and about 3% iron. It is among the strongest bronzes: about 690–760 MPa tensile, with excellent corrosion and wear resistance in seawater, and high cavitation-erosion resistance.
It is used for aerospace bushings (for example in landing gear), marine shafts and valves, gears and highly loaded parts in corrosive environments. In cast form (C955 and C958) it is the classic material for ship propellers.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 620–720 MPa | database value |
| Yield strength Rp0.2 | 280–380 MPa | database value; per Concast (HR50) about 470 |
| Elongation A | 12% | |
| Hardness | 170–195 HB | |
| Modulus of elasticity E | 114 GPa | |
| Density ρ | 7.45 g/cm³ | |
| Machinability | 50% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Al aluminum | 9.0–11.0 | strength and oxide film |
| Ni nickel | 4.0–5.5 | strength and corrosion resistance |
| Fe iron | 2.0–4.0 | |
| Mn manganese | max 1.5 | |
| Si silicon | max 0.25 | |
| Zn / Sn | max 0.30 / 0.20 | |
| Cu copper | balance |
Per the copper.org UNS table and Concast data.
Tempers and heat treatment
Aluminum bronzes with more than about 9% aluminum can be hardened and tempered, much like steel. A suitable heat treatment also improves corrosion resistance (prevents "dealuminification").
| Condition | Properties | When to choose it |
|---|---|---|
| Drawn and stress relieved (HR50) | per Concast: Rm about 760, yield about 470 MPa | bar |
| Quench hardened and tempered (TQ50) | higher strength | highly loaded parts (for example C63020) |
Applications
- Aerospace bushings
- Marine shafts and valves
- Gears
- Pump parts
- Loaded parts in corrosive environments
Fabrication
Welding
Welds well, with matching NAB filler.
Corrosion
Excellent in seawater. Proper heat treatment prevents dealuminification in crevices.
Machining
Moderate, and relatively strong for a bronze.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| C614 | 550–600 / 280 MPa | Excellent | without nickel: weaker · material page |
| C954 | 552–690 / 241–379 MPa | Excellent | a cast aluminum bronze · material page |
| C706 (CuNi 90/10) | 315 / 125 MPa | Good | copper-nickel for piping · material page |
Common mistakes
Running it against steel without lubrication under high load
Even a strong bronze needs lubrication.
Ignoring heat treatment in marine service
An unsuitable structure is prone to dealuminification.
Substituting C614 in a critical part
C630 is much stronger.
Equivalents, standards and supply
| EN | CW307G |
|---|---|
| DIN | CuAl10Ni5Fe4 |
| Standards | ASTM B150 / AMS 4640 |
| Forms | rod · forging · bearing |
| Producers | Diehl · Lebronze · Columbia Metals |
Learn more
Values are typical and for comparison only. For design, rely on the standard and the mill certificate. Sources: Copper Development Association (copper.org), ASTM B111 and B124, producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026