Steel 9CrSi · temper · default condition
Steel 9CrSi Annealed
Properties of the Annealed condition, compared with the other 9CrSi tempers.
Use the spheroidize-annealed ≤241 HB delivery state at 217 HB for turning, milling, drilling, tapping and forming, then quench and temper to service hardness.
What is 9CrSi Annealed?
9CrSi Annealed is 9CrSi in the Annealed temper — use the spheroidize-annealed ≤241 HB delivery state at 217 HB for turning, milling, drilling, tapping and forming, then quench and temper to service hardness. 9CrSi Annealed has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 51% of steel grades. Elongation at break is 15% and the elastic modulus is 210 GPa (30.5 Msi). 9CrSi Annealed has a density of 7.77 g/cm³ (0.281 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 77% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
9CrSi Annealed properties
Typical room-temperature values for 9CrSi Annealed — 10 properties are specific to this condition; the rest are grade-level values shared by every 9CrSi temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
9CrSi Annealed has a density of 7.77 g/cm³ (0.281 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
9CrSi Annealed has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 51% of steel grades. Elongation at break is 15% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
9CrSi Annealed is rated for continuous service to 300°C (572 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
9CrSi Annealed conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of 9CrSi Annealed takes about 33 MJ of energy and emits 2.4 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 30%.
Manufacturability8
9CrSi Annealed's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (15/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 9CrSi tempers and conditions
9CrSi is also supplied in 8 other conditions. The full side-by-side table is on the 9CrSi overview.
- AnnealedDefaultUse the spheroidize-annealed ≤241 HB delivery state at 217 HB for turning, milling, drilling, tapping and forming, then quench and temper to service hardness.430 MPa yield · 217 HB
- Q&T 60-62 HRCChoose for cutting tools — taps, reamers, dies, shear blades — needing maximum wear resistance; oil quench plus a 160–200 °C temper gives 61 HRC with little toughness reserve.2,250 MPa tensile
- Q&T 56-60 HRCUse for cold stamping dies and thread-rolling plates that must balance toughness and wear; the 200–300 °C temper after oil quench holds about 58 HRC and 2050 MPa tensile.2,050 MPa tensile
- Q&T 50-55 HRCPick for cutting edges and die parts under higher impact loads; the 300–400 °C temper trades hardness down to about 53 HRC and 1750 MPa tensile in exchange for toughness.1,550 MPa yield · 53 HRC
- Q&T 45-50 HRCChoose when toughness governs, as in spring clamps and impact-loaded tooling; tempering at 400–500 °C lowers hardness to about 47 HRC and clearly reduces wear resistance.1,350 MPa yield · 47 HRC
Working with 9CrSi Annealed
Is 9CrSi easy to machine?
Machine in the annealed condition (≤241 HB) with coated carbide or high-cobalt HSS; the high silicon makes chips slightly sticky and accelerates tool wear. Once hardened, work only by grinding or EDM.
Can 9CrSi be welded?
High carbon and hardness make it crack-sensitive, so it is normally not welded. For unavoidable repair use matching or martensitic stainless electrodes with 300–400 °C preheat, maintained interpass temperature and an immediate post-weld temper.
Can 9CrSi be formed, bent or molded?
Forge in the 1100–850 °C range, cool slowly and spheroidize-anneal promptly after forging. Cold forming capability is very limited — light straightening and coining only.
What surface finishes work on 9CrSi?
Grind and polish after quench and temper. Protect with black oxide, phosphating, steam treatment or oil; TiN coating is possible if the coating temperature stays below the tempering temperature.
9CrSi chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.85 – 0.95 | 0.9 |
| Siraises hardenability and temper stability; promotes decarburization | 1.2 – 1.6 | 1.4 |
| Mn | 0.3 – 0.6 | 0.45 |
| Cr | 0.95 – 1.25 | 1.1 |
| Pimpurity upper limit | ≤ 0.03 | — |
| Simpurity upper limit | ≤ 0.03 | — |
| Niresidual element | ≤ 0.25 | — |
| Curesidual element | ≤ 0.3 | — |
| Fe | balance | — |
9CrSi Annealed — frequently asked
What is 9CrSi Annealed used for?
9CrSi Annealed is typically used for taps and thread dies, reamers and broaches, cold blanking and punching dies, shear and guillotine blades, thread-rolling plates and cold-work punches. In short: cold-work tool steel.
What is the yield strength of 9CrSi Annealed?
9CrSi Annealed has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 9CrSi Annealed easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed condition (≤241 HB) with coated carbide or high-cobalt HSS; the high silicon makes chips slightly sticky and accelerates tool wear. Once hardened, work only by grinding or EDM.
Can 9CrSi Annealed be welded?
Not readily — weldability is rated poor (15/100). High carbon and hardness make it crack-sensitive, so it is normally not welded. For unavoidable repair use matching or martensitic stainless electrodes with 300–400 °C preheat, maintained interpass temperature and an immediate post-weld temper.
What surface finishes work on 9CrSi Annealed?
Grind and polish after quench and temper. Protect with black oxide, phosphating, steam treatment or oil; TiN coating is possible if the coating temperature stays below the tempering temperature.
Can 9CrSi Annealed be formed, bent or molded?
Forge in the 1100–850 °C range, cool slowly and spheroidize-anneal promptly after forging. Cold forming capability is very limited — light straightening and coining only.
What is the maximum service temperature of 9CrSi Annealed?
9CrSi Annealed is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 9CrSi Annealed?
Yes — 9CrSi Annealed is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (tool steels) — ASM International (1990)
- 1.2108 / 90CrSi5 cold-work tool steel data (equivalent grade) — European tool-steel producers (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.