Surface treatment
The finishes we supply
Anodizing, oxide and marking
- CoatingBlack oxide
- CoatingAnodizing, Type II / Type III
- MarkingLaser marking
Plating, coating and hardening
- PlatingZinc with clear, blue, yellow or black chromate, and zinc-nickel (ASTM B633 / ISO 4042)
- PlatingElectroless nickel
- PlatingThin dense chrome
- CoatingPVD, powder coating, passivation
- HeatHeat treatment and hardening
Black zinc plating: black chromate must be specified | Coating type and color confirmed before plating.
Heat treatment
The conditions we specify and check
| Process | What it does | Grades we run it on | Typical result |
|---|---|---|---|
| Stress relief | Takes out the stress left by welding and heavy roughing so the part does not move on the finishing cuts. | SS400 · S355JR welded frames · 6061 plate | Dimensional stability; hardness change controlled by process route |
| Annealing | Softens the steel so it can be cut. The hardening comes afterwards, not before. | SUJ2 · SKD11 · SKD61 before machining | Machinable condition, SUJ2 typically under 210 HB |
| Normalizing | Refines and evens out the grain after hot working so machining behaves predictably. | S20C · S45C · SS400 | Uniform structure through the section |
| Through hardening (quench and temper) | Hardens the section, tempers to the mechanical properties on the drawing. | SCM440 / 4140 · SNCM439 / 4340 · S45C · S50C | 4140 HT commonly 28–34 HRC; higher on request |
| Case hardening (carburizing) | Puts a hard wearing skin over a core that stays tough. Case depth is a drawing item, not a default. | S20C / 1020 bushings, pins, wear plates | Case typically 58–62 HRC over a soft core |
| Induction hardening | Hardens only the running surface of a shaft and leaves the rest of the part alone. | S45C / 1045 shafts and pins | Typically 45–55 HRC on the hardened band |
| Tool steel hardening | Harden and temper several times for dies, punches and hot-work tooling. | SKD11 / D2 · SKD61 / H13 | SKD11 typically 58–62 HRC · SKD61 typically 44–52 HRC |
| Precipitation hardening (aging) | On PH stainless the aging condition is part of the specification, not an option. H900 and H1075 are different materials in practice. | SUS630 / 17-4PH · 15-5PH | H900 about 40–44 HRC · H1075 about 32–36 HRC |
| Solution treat and artificial aging | The T temper on aluminium is a heat treatment. T6 and T651 are not the same stock condition. T651 is plate that has been stress-relieved. | 6061-T6 / T651 · 7075-T6 · 6063-T5 / T6 | Supplied in temper; we don't re-heat-treat aluminium in process |
Heat treatment per drawing | Hardness check: Mitutoyo QMH 14BX before shipment.
Hardness in the table: reference values | Acceptance requirements: heat treatment condition, hardness and case depth on the drawing.