Ni-Hard
A martensitic Ni-Cr white iron, abrasion resistant
Typical values for the temper in the title
Ni-Hard is a nickel-chromium white iron, defined in ASTM A532 as Class I. Nickel lets the structure transform to hard martensite, and chromium keeps carbon as carbides. Typical hardness is 500–600 HB.
The most common type is Type D, called Ni-Hard 4: about 9% chromium and about 5–7% nickel. Compared with older types, it has better toughness. It is used for slurry pump casings, mill liners, grinding balls and wear parts.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 550 MPa | database value; brittle material |
| Elongation A | <1% | |
| Hardness | 550-700 HB | database value |
| Modulus of elasticity E | 170 GPa | |
| Density ρ | 7.6 g/cm³ | |
| Machinability | grinding only | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| C carbon | 2.5–3.6 (Type D) | carbides |
| Cr chromium | 7.0–11.0 (Type D) | hard carbides |
| Ni nickel | 4.5–7.0 (Type D) | martensitic structure |
| Mn / Si | max 2.0 each | |
| Mo molybdenum | max 1.5 | |
| Fe iron | balance |
The Type D (Ni-Hard 4) composition per Wilfley data and ASTM A532.
Grades and conditions
Ni-Hard is stress relieved and sometimes hardened, to obtain a stable martensitic structure.
| Grade / condition | Properties | When to choose it |
|---|---|---|
| Type A / B (Ni-Hard 1 / 2) | about 3–5% nickel, relatively low chromium | older types |
| Type D (Ni-Hard 4) | about 9% chromium; per Wilfley 600–655 HB | the most common, tougher |
Applications
- Slurry pump casings
- Mill liners
- Grinding balls
- Mining wear parts
- Pipes and elbows for abrasive materials
Fabrication
Processing
Grinding only.
Welding
Very poor. Not suitable.
Impact
Sensitive to impact fracture, but Type D is tougher than the older types.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| White Cast Iron | 140-200 / — | Not possible | general white iron, classes II and III · material page |
| Hardox 400 | 1250 / 1000 MPa | Medium | an abrasion-resistant steel: more impact resistant · material page |
| D2 | 800 MPa anneal / — | Not recommended | a tool steel: machinable before hardening · material page |
Common mistakes
Choosing Ni-Hard for wear with heavy impact
The material is brittle. For wear with impact, consider an abrasion-resistant steel.
Planning machining
Plan a near-net-shape casting and grinding.
Ordering without stating a type
Type D differs from the older types in composition and toughness.
Equivalents, standards and supply
| EN | EN-GJN-HV600 (close) |
|---|---|
| ASTM | A532 Class I |
| Standards | ASTM A532 Class I |
| Forms | casting |
| Producers | Bradken · ME Elecmetal |
Learn more
Values are typical and for comparison only. In cast iron, properties depend strongly on wall thickness and cooling rate in casting. For design, rely on the standard and test-bar results. Sources: ASTM A48, A536, A897, A532, A439 and EN 1561/1563/1564, producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026