Invar

Nickel alloy with a very low coefficient of thermal expansion.

Invar at a glance
Common grades
Invar 36 · Super Invar
Machinability
Invar exists for one property: a coefficient of thermal expansion close to one-tenth of steel's.
Tolerances
±0.025 mm standard on linear dimensions; ±0.010 mm on critical features
Processes
CNC milling, CNC turning and 5-axis machining
Finishes
Stress-relief / stabilization cycles · Nickel plating · Black oxide
Used in
Optics, Semiconductor
Certification
Mill test certificate (chemistry and mechanical properties) with every lot; EN 10204 3.1 certificates on request

Machining Invar

Invar exists for one property: a coefficient of thermal expansion close to one-tenth of steel's. Parts that must not move with temperature (optical benches, laser and telescope mounts, metrology fixtures, semiconductor stage components) are why the alloy is specified despite its cost.

Machining Invar is about protecting that stability. The alloy is gummy, work-hardens, and locks in residual stress that can release later as distortion. We sequence rough machining, stress relief, and finish machining so the part you install is the part that stays put.

We hold ±0.025 mm on critical Invar features and can plan additional stabilization cycles where the drawing's flatness or long-term stability requirements demand it.

Common Grades We Machine

  • Invar 36 - The standard grade: ~1.2 ppm/°C expansion near room temperature for dimensionally critical structures.
  • Super Invar - Even lower expansion over a narrower temperature band, for the most demanding optical assemblies (sourced on request).

Applications by Industry

  • Optics - mounts, benches and structural members that hold optical alignment through temperature swings.
  • Semiconductor - stage and metrology components where nanometre-level stability is the requirement.

Surface Finishing Options

  • Stress-relief / stabilization cycles - sequenced with machining so residual stresses don't release as distortion later.
  • Nickel plating - corrosion protection: bare Invar rusts like carbon steel.
  • Black oxide - a low-reflectance protective finish for optical environments.

See our surface finishing services for the full range.

Frequently Asked Questions

Why machine Invar instead of aluminium or steel?

Only when thermal stability is the requirement: Invar expands about a tenth as much as steel with temperature. For optical alignment and metrology, that stability is the entire point of the material.

How do you prevent Invar parts distorting after machining?

By sequencing: rough machine, stress-relieve, then finish machine, with additional stabilization cycles where flatness or long-term stability requirements are severe.

Does Invar corrode?

Yes. It behaves like carbon steel. We typically nickel plate or black oxide finished parts unless your assembly controls the environment.

Precision Invar Manufacturing in Singapore

Need complex Invar parts manufactured to tight tolerances? Explore our 5-axis simultaneous CNC machining, CNC milling, CNC turning and certified ISO Class 6–8 cleanroom assembly capabilities.

Speak with Our Sales & Engineering Team

Explore how Shine's Singapore precision CNC machining and cleanroom assembly integrate into your global supply chain. We welcome technical consultations, mutual NDAs, and facility audits.

  • Mutual NDA executed within 24 hours
  • ISO 9001:2015 certified & Cyber Essentials mark
  • 24–48h engineering DFM feedback & formal RFQ pricing