C95800 (NAB)
A marine cast nickel-aluminum bronze
Typical values for the temper in the title
C95800 is a nickel-aluminum bronze with less aluminum (about 9%) than C95500, and a little manganese. It is less strong (minimum 585 MPa), but much more ductile (minimum 15% elongation), and has excellent resistance to corrosion, erosion and cavitation in seawater.
It is the standard bronze for ship propellers, seawater pump casings and valves, and marine and subsea parts.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | ≥585 MPa (B148) | |
| Yield strength Rp0.2 | ≥240 MPa (B148) | |
| Elongation A | ≥15% | |
| Density ρ | 7.64 g/cm³ | |
| Machinability | 50% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Al aluminum | 8.5–9.5 | strength |
| Ni nickel | 4.0–5.0 | corrosion |
| Fe iron | 3.5–4.5 | strength |
| Mn manganese | 0.8–1.5 | |
| Cu copper | min 79 |
Composition and minimum properties per ASTM B148 (ICAST, copper.org).
Tempers and heat treatment
Cast bronzes are ordered by casting method (sand, centrifugal, continuous), and minimum properties differ for each method.
| Condition | Properties | When to choose it |
|---|---|---|
| Sand cast | Rm ≥585, Rp ≥240 MPa, A ≥15% | propellers and castings |
| Continuous cast (B505) | bars | machining into parts |
Applications
- Propellers
- Seawater pump casings
- Seawater valves
- Subsea parts
- Seawater cooling systems
Fabrication
Machining
Moderate (about 50%). Strong and hard, so sharp tools and a rigid machine.
Welding
Good by electric arc. Not oxyacetylene.
Corrosion
Highly resistant in seawater, but prone to "dealuminification" if heat treatment or composition is wrong.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| C95500 (NAB) | ≥620 MPa (B148) / ≥275 MPa (B148) | Good — not oxyacetylene | C95500: stronger, less ductile · material page |
| C71500 (CuNi 70/30) | — / | Good — CuNi 70/30 filler | C71500: copper-nickel for piping · material page |
| C954 | 552–690 / 241–379 MPa | Excellent | C95400: aluminum bronze without nickel · material page |
Common mistakes
Choosing C95500 for a propeller
C95800 is more ductile and seawater resistant.
Ignoring composition and treatment
They determine dealuminification resistance.
Oxyacetylene welding
Not recommended.
Equivalents, standards and supply
| UNS | C95800 |
|---|---|
| Standards | ASTM B148 / ASTM B505 / ASTM B271 |
| Forms | casting · continuous-cast bar |
| Producers | Concast · National Bronze |
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