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Case

Hardmetal case (tungsten carbide composite)

High confidence

The case material of the original DiaStar and of Rado's hardmetal production generally: a cemented carbide, the same material class used for industrial cutting tools, in which ceramic hardness is combined with metallic binder toughness. Roughly twice the density of steel and far harder; correspondingly more brittle.

Part reference

Brand
Rado
Material
Tungsten carbide in a metal binder
Introduced
1962

Documented variations

Classification

FactoryDocumented as shipped from the factory for this reference and period.PeriodNot original to this watch, but correct for its production period.ServiceFitted by the manufacturer's own service network. Not a defect.AftermarketThird-party part. Affects originality, not authenticity.ModifiedGenuine parts in a configuration the factory did not sell. Affects originality and value, not authenticity.CounterfeitDeceptive reproduction intended to pass as genuine.UnknownEvidence on file does not settle the question.

  • Unscratched after decades of wear

    FactoryProbable

    Whole production

    The expected condition. Hardmetal does not acquire the fine scratch haze that a worn steel case does, and its absence on a sixty-year-old watch is confirmation rather than a sign of refinishing.

  • Chipped at an edge

    FactoryProbable

    Whole production

    Consistent with the material and with an impact. Hardness is not toughness: this material chips where steel would dent. Condition, not a finding against the watch — and incidentally corroboration that the case is what it claims.

  • Scratched, light, or worn through to another metal

    CounterfeitProbable

    Whole production

    All three are inconsistent with hardmetal and all three point the same way: plated steel. Weight is the quickest of the three to judge, scratch haze the most visible, and plating worn through at an edge the most conclusive.

Documented on these references

  • Rado DiaStar 1 (1962)Factory

    1962 →

    Weight and scratch behaviour both apply here. They do NOT apply to the modern steel-cased DiaStar Original.

Provenance of this record

Sources & Evidence

Primary sourceTechnical documentation

Technical literature on engineering ceramics and cemented carbides

Materials-science and industrial technical literature

Accessed
2026-08-19

Cited for

This referenceHigh confidence
Primary sourceManufacturer documentation

Rado — collection specifications and material documentation

Rado (Swatch Group)

Accessed
2026-08-19

Cited for

This referenceHigh confidence
View source ↗

Last verified: Not yet reviewed