O6
Data under reviewO6 is a graphitic oil-hardening tool steel: free graphite particles in its microstructure act as a solid lubricant. It resists galling and seizing in sliding contact better than any other tool steel class.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 1.25–1.55 |
| Si | 0.55–1.20 |
| Mn | 0.30–1.10 |
| Mo | 0.20–0.40 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness (hardened) | 55–60 HRC |
| Density | 7.85 g/cm³ |
| Self-lubrication | Graphite in microstructure |
Heat treatment
Harden 790–840 °C oil; temper 150–260 °C. Silicon promotes free graphite during annealing.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | O6 |
Compare side by side: O6 vs O1 · O6 vs O2
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Bushings, arbors, forming rolls, guide pins, dies sliding against soft metals, parts that seize in service.
Processing: Machines very easily — the graphite aids chip breaking. Wear resistance is moderate; not for heavy abrasive duty.
FAQ
- Why choose a graphitic steel?
- Where the failure mode is galling or adhesive pick-up rather than abrasion — the graphite film keeps sliding surfaces from welding to the workpiece.
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Ask for a quotationVisit NasteelSource: ASTM A681 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.