Sherardized steel grating and small steelwork
Sherardized finish for enhanced corrosion resistance in demanding environments. Zinc diffusion coating provides durable protection.
Welded bar grating with a sherardized (zinc diffusion) coating — a dry, heat-based zinc treatment that produces an even, matte-grey finish with excellent corrosion resistance and paint adhesion. Unlike hot-dip galvanizing, sherardizing does not involve molten zinc immersion, which means no risk of warping thin-section panels and a more uniform coating thickness.
What is sherardizing?
Sherardizing is a thermo-chemical diffusion process: grating panels are tumbled in a sealed drum with zinc dust at 380–400 °C. Zinc atoms diffuse into the steel surface, forming a series of iron-zinc alloy layers (delta and gamma phases). The result is a hard, metallurgically bonded coating that is:
- Uniform in thickness — no drips, runs, or bare spots, even on complex crossing geometry.
- Excellent for paint adhesion — the matte surface profile accepts powder coat or wet paint without extra preparation (ideal for duplex systems).
- Hydrogen embrittlement–free — important for high-strength or hardened components.
- Dimensionally precise — coating thickness is typically 15–45 µm, so bearing bar pitches and panel dimensions stay within tolerance.
Sherardized vs. hot-dip galvanized
| Property | Sherardized | Hot-dip galvanized |
|---|---|---|
| Process | Zinc diffusion at 380–400 °C | Immersion in molten zinc at ~450 °C |
| Coating thickness | 15–45 µm (controllable) | 45–85 µm (variable) |
| Surface finish | Matte grey, uniform | Shiny to spangled, may have drips |
| Paint adhesion | Excellent (no prep needed) | Requires sweep blasting or etch primer |
| Warping risk | Minimal | Higher on thin panels |
| Cost | Higher per piece | Lower per piece at volume |
| Best for | Precision panels, duplex systems, architectural | General industrial, bulk orders |
Specifications
| Parameter | Details |
|---|---|
| Finish | Sherardized zinc diffusion (BS EN 13811 / ISO 17668) |
| Material | Carbon steel Q235B / A36 / S235JR |
| Construction | Welded or press-locked — same grating types as standard welded grating |
| Coating thickness | 15–45 µm (specify in RFQ or per project spec) |
| For RFQ | Grating type, pitches, panel sizes, environment, coating class |
For a full comparison of available finishes, see Materials & Finishes.
Where sherardizing is specified
Data centers
Clips and small hardware bundles shipped with raised-floor or cable-tray packages needing uniform zinc diffusion in threads.
Power generation
Attachment kits for maintenance platforms in corrosive indoor atmospheres where hot-dip tank size is awkward for mixed small parts.
Oil & gas
Fastener-adjacent components in modules where galvanizing drips are unacceptable but zinc protection is still required.
Related
Compared to hot-dip galvanizing
Sherardizing diffuses zinc onto steel in a batch process suited to complex small sections. Large walk-off panels more often use hot-dip galvanized welded grating.
Frequently asked questions
What thickness of zinc is typical?
Depends on process cycle and part geometry; request a coating thickness range on the mill sheet.
Can full walkway panels be sherardized?
Less common than batch small parts—ask for maximum single-piece size limits.
Touch-up after field cutting?
Follow zinc repair guidance similar to other zinc systems.
Stainless alternative?
Where chlorides dominate, compare to stainless meshes.
ASTM or ISO references?
List required test reports in the RFQ for supplier alignment.
Batch size limits?
Ask maximum part length/weight per furnace charge—oversized panels may need hot-dip instead.
Need a quotation?
Send product type, spacing, material, finish, panel size, quantity, and drawings.