Hardness & wear
Hardness acceptance criterion Required by the standard
| Condition | Criterion |
|---|---|
| Solution heat treated (sheet, plate, bar) | 33 – 43 HRC |
Hardness must be 33 to 43 HRC, determined to ASTM E18.
⚠ This is a TWO-SIDED band, with both a floor and a ceiling, unlike the single-sided criteria of the two cast grades in the same family. The 10-point HRC width reflects the normal spread of carbide distribution in wrought material after solution treatment.
This grade is Stellite 6B, the wrought version of Stellite 6: the same Co-28Cr-4.5W-1.15C composition, but rolled and solution treated rather than cast, which is why it carries a tensile table where the cast version does not.
⚠ Three cobalt wear alloys in the same family, three different directions of hardness requirement — read the direction before the number:
· R30006 (Stellite 6 castings) — not lower than 37 HRC: a minimum, because the hardness is the function;
· R30021 (Stellite 21 castings) — as-cast not higher than 34 HRC: a maximum, because the alloy age-hardens further in service;
· R30016 (Stellite 6B wrought) — 33 to 43 HRC: a two-sided band.
When you see a cobalt hardness figure, establish first whether it is a floor, a ceiling or a range.
What the standard says about wear service Informative only — not a basis for acceptance
Typical uses: parts that need wear resistance and minimal galling or seizing at room and elevated temperatures; use is not limited to these.
⚠ The sentence names galling and seizing specifically, which is not the same thing as abrasive wear. What cobalt alloys are good at is not sticking under metal-to-metal contact, and that is the property to look at when choosing valve seats, guide faces and sealing faces. For abrasive service with hard particles — digging, conveying — separate abrasion data is needed.
⚠ Unlike the Stellite 6 castings, no temperature ceiling is named, and no elevated-temperature mechanical values are specified.
Condition as supplied and heat treatment Required by the standard
| Sheet and plate | Hot- or cold-rolled and solution heat treated; unless solution treatment is done in an atmosphere yielding a bright finish, descaled to a No. 1 finish per ASTM A480/A480M and AS4194 |
| Bar | Solution heat treated with a turned or ground finish; bars shall not be cut from plate |
| Solution heat treatment | 1232 °C ± 14 °C (2250 °F ± 25 °F), held for a time commensurate with cross-section but not less than 15 min, cooled at a rate equivalent to still air or faster; pyrometry per AMS2750 |
| Size range covered | Sheet and plate up to 25 mm nominal thickness; round bar up to 89 mm nominal diameter |
⚠ Bars must not be cut from plate — a hard rule that is easy to work around: strips cut from plate and sold as bar have the wrong grain direction and the wrong test orientation, since bars are tested longitudinally and sheet and plate transversely.
⚠ For product outside the standard size range, the mechanical requirements are agreed between purchaser and producer and stated in the report. For plate over 25 mm or bar over 89 mm the specification sets no minima.
⚠ Reduction of area does not apply to plate or sheet under 12.7 mm nominal thickness.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements6 elements | |||
| Co | Cobalt | Bal. | |
| Cr | Chromium | 28 – 32% | |
| W | Tungsten | 3.5 – 5.5% | |
| Mn | Manganese | 0.5 – 2% | |
| C | Carbon | 0.9 – 1.4% | |
| Si | Silicon | 0.2 – 2% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual5 elements | |||
| Ni | Nickel | ≤ 3% | |
| Mo | Molybdenum | ≤ 1.5% | |
| Fe | Iron | ≤ 3% | |
| P | Phosphorus | ≤ 0.04% | |
| S | Sulphur | ≤ 0.03% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % |
|---|---|---|---|---|
| Sheet, plate and bar | Solution heat treated | ≥ 896 (130 ksi) | ≥ 483 (70 ksi) | ≥ 5 |
Where this grade is recommended
Matched in 1 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Valves, fittings & flanges | Oil & Gas | > 300 °C | 10 / 14 | 82 |
Designations & equivalents
| EN designation | CoCr30W4 |
| Trade name(s) | Stellite 6B / 6K |
| AMS (SAE aerospace) | 5894 |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
Name the standard and its edition on the order.
Frequently asked questions
What is Stellite 6B (wrought) · UNS R30016?
Stellite 6B (wrought) · UNS R30016 — Co-Cr-W (Stellite). The wrought 6 — erosion shields, scraper blades, sleeves
What is the maximum service temperature of R30016?
Typically about 800 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of R30016?
The specified minimum tensile strength is 896 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover R30016?
SAE AMS 5894 Co-28Cr-4W-1.1C Stellite 6B
Where is R30016 typically used?
Valves, fittings & flanges (Oil & Gas)
In which forms is R30016 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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