MATERIAL COMPARISON
A similar density does not make two heavy alloys equivalent.
WNiFe and WNiCu identify different tungsten heavy-alloy families. For purchasing, distinguish the exact grade from a broad family label, especially when the component has a magnetic-response requirement.
Comparison at a glance
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| Criterion | WNiFe | WNiCu |
|---|---|---|
| Binder family | Nickel-iron. | Nickel-copper. |
| Named manufacturer example | Plansee DENSIMET, NiFe-based grades. | Plansee INERMET, NiCu-based grades. |
| Magnetic classification of those examples | Weakly ferromagnetic in the cited Plansee brochure. | Paramagnetic in the cited Plansee brochure. |
| Density and strength for purchasing | Request values for the exact grade, product form and supplied condition. | Request values for the exact grade, product form and supplied condition. |
| Acceptance and substitution | Agree the magnetic test and limit; obtain approval before replacing a specified WNiCu grade. | Agree the magnetic test and limit; obtain approval before replacing a specified WNiFe grade. |
This is a qualitative procurement summary, not a copied manufacturer property table. The magnetic descriptions apply only to the named examples. Neither family name specifies a universal density, strength or acceptance limit.
A manufacturer-specific magnetic distinction
Plansee’s September 2021 W-MMC brochure classifies its NiFe-based DENSIMET grades as weakly ferromagnetic and its NiCu-based INERMET grades as paramagnetic. These classifications describe the named manufacturer materials, not every product sold under a family abbreviation.
Plansee W-MMC, September 2021, pages 4 and 6 (external PDF, English)
Define the magnetic requirement
If magnetic response is important, specify the measurable requirement and relevant test conditions rather than relying only on the word non-magnetic. Ask whether the offered grade is documented against that requirement.
Compare the exact grade
Keep the alloy designation and supplied condition attached to each property value. Matching a density description alone does not demonstrate matching mechanical, magnetic or processing behaviour.
Separate an alternative from a match
A WNiFe offer against a WNiCu drawing, or the reverse, should be clearly identified as a proposed alternative. Obtain approval from the party responsible for the specification before treating it as an acceptable substitute.
What to include in the comparison
- Record the material designation exactly as requested and exactly as offered.
- Compare quotations for the same form, dimensions and quantity.
- Place any project-specific magnetic requirement or drawing reference in Technical Requirements / Notes.
- Ask for evidence applicable to the delivered material; a trade name or a general brochure is not a shipment-specific test result.
This page does not assign universal permeability, strength or density values to either family. The cited brochure is a dated reference, not a statement of current stock, authorisation to use a trade name or proof of compliance for an offered product.
Continue with the material pages
Source reviewed: 11 October 2026. Original procurement guidance by MNK-G.S.A.