Coating · zinc diffusion
Sherardized
A zinc diffusion coating: parts are heated in a drum with zinc powder below the melting point of zinc. The layer follows threads and edges evenly. Specified in classes by minimum thickness in EN ISO 17668.
Sprechen Sie mit Terry · Sales Engineer
Was es ist
How Sherardized protects the joint.
01Diffusion, not a deposit on topZinc diffuses into the steel surface and forms zinc-iron layers.
02Even on threadsThe layer follows the shape of the part, including threads and edges.
03No electrolysisNo electroplating step – used for high-strength and hardened parts where hydrogen embrittlement must be avoided.
Applications
Where we use it.
01High-strength fastenersBolts and screws where electroplating is not wanted.
02Small parts in bulkProcessed in a rotating drum.
03Fine tolerancesParts where an even layer on the thread matters more than maximum thickness.
Layer thickness
Thickness, fit and threads.
Layer thickness
15 · 30 · 45µm
Classes from EN ISO 17668, by minimum local thickness. The layer adds to the outside dimensions – threads need extra clearance.
| Class (EN ISO 17668) | Minimum thickness |
|---|---|
| Class 15 | 15 µm |
| Class 30 | 30 µm |
| Class 45 | 45 µm |
How it is applied
From bare steel to coated part.
01ReinigenCleaning to bare steel.
02DrumParts tumble with zinc powder in a sealed, heated drum.
03DiffusionZinc diffuses into the surface below its melting point (419 °C).
04CheckLayer thickness checked against the ordered class.
FAQ
Questions we get about Sherardized.
- Sherardized or hot-dip galvanized?
- Sherardizing gives a more even layer on threads at lower process temperature; HDG is thicker.
- Which class do I need?
- Thicker classes give longer life but need more thread clearance. Tell us the environment and thread.
- Is there a hydrogen-embrittlement risk?
- Sherardizing involves no electroplating step – one reason it is chosen for hardened parts.
Next step
Quote, compare or ask.
Reviewed October 2026 by HBS Solutions. Based on EN ISO 17668. Corrosion results always belong to a complete system (pretreatment, coating, thickness) – ask us for the data sheet of the system you order.
Other coatings
Compare with another coating.
TAKECOAT-1000Fluorocarbon polymer, 2 layersXylan 1070PTFE dry film, solvent-borneXylan 1424PTFE dry film, waterborneXylan 1427PTFE, extra corrosion protectionGeomet 500Zinc flake, integral lubricantHot-dip galvanizedISO 10684 · min 50 µm averageZinc platedElectroplated zinc · ISO 4042All coatingsCompare them side by side
ANGEBOT INNERHALB VON 24 STUNDEN
Senden Sie uns Ihre Stückliste.
Bestätigung am selben Tag. Ein vollständiges Angebot innerhalb von 24 Stunden.
ANGEBOT ANFORDERN →
IHR ANSPRECHPARTNERSprechen Sie mit TerrySales Engineer01E-Mailsales@hbssolutions.nl02WhatsAppChatten Sie mit unseren Ingenieuren
03Rufen Sie mich zurückHinterlassen Sie Ihre Nummer – Terry ruft Sie an