Hydrogen Embrittlement — is baking required?
For electroplated high-strength fasteners, check whether de-embrittlement baking is indicated and see the reference bake window.
Why it matters
Hydrogen picked up during acid pickling and electroplating can cause delayed fracture of high-strength steel. ISO 4042 and ASTM B850/F1940 call for a baking (relief) treatment above a strength/hardness threshold. This tool is a reference indicator — the drawing and specification prevail.
Borderline — treat as required
The strength is close to the threshold. Treat baking as required unless the specification says otherwise.
Reference bake window
Typically 190–230°C, held 4–24 h (longer for higher strength — ≥1400 MPa parts need longer holds), started as soon as possible and within about 1–4 h of plating. Reference values per ISO 4042 / ASTM B850; the governing specification prevails. We run de-embrittlement baking in-house with logged time and temperature.
This is a reference indicator, not an approval
- •Conversions between HRC / HV / MPa are approximate — verify against the actual test.
- •The governing drawing, customer specification or standard sets the real requirement and bake parameters.
- •Baking must start soon after plating; delayed baking is far less effective.