Steel 9CrSi Hardened 63-65 HRC
Hardness band
GB 9CrSi
Hardened 63-65 HRC = as-quenched
Treat only as an intermediate state straight from the 860–880 °C oil quench; temper immediately to relieve quenching stress, otherwise cracking is likely at 64 HRC.
Values for the Hardened 63-65 HRC condition
Other 9CrSi tempers and conditions
9CrSi is listed in 9 conditions; see the grade overview at 9CrSi.
- Annealed
- Stress Relieved
- Hot Rolled
- Cold Drawn
- Q&T 45-50 HRC
- Q&T 50-55 HRC
- Q&T 56-60 HRC
- Q&T 60-62 HRC
- Hardened 63-65 HRC
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize/soft annealed ( , ≤241 HB) | 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. | 430 | 750 | 15 | 217 HB | — |
600–700 °C after rough machining | Apply at 600–700 °C after rough machining to relieve stress and limit quench distortion in slender tools and precision dies; at 225 HB it is not a final service condition. | 450 | 770 | 14 | 19 HRC | 7 % IACS |
as-rolled bar/flat, un-annealed | Choose as-rolled bar or flat at 280 HB as the most economical supply form for large sections; spheroidize annealing is normally required before machining. | 570 | 900 | 10 | 29 HRC | 7 % IACS |
annealed then cold drawn/peeled bar | Pick annealed then cold drawn or peeled bar for small-diameter tap and reamer blanks: size accuracy and surface allow direct hardening, but elongation falls to 8%. | 700 | 880 | 8 | 26 HRC | 7 % IACS |
Oil quench + temper 400–500 °C | Choose 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 | 1,550 | 6 | 47 HRC | 6.5 % IACS |
Oil quench + temper 300–400 °C | Pick 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 | 1,750 | 3 | 53 HRC | 6.5 % IACS |
Oil quench + temper 200–300 °C | Use 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. | 1,820 | 2,050 | 1.5 | 58 HRC | 6 % IACS |
Oil quench + temper 160–200 °C | Choose 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. | 2,000 | 2,250 | 1 | 61 HRC | 6 % IACS |
Hardened 63-65 HRCThis page As-quenched | Treat only as an intermediate state straight from the 860–880 °C oil quench; temper immediately to relieve quenching stress, otherwise cracking is likely at 64 HRC. | 2,050 | 2,300 | 0.5 | 64 HRC | 5.7 % IACS |
What is 9CrSi Hardened 63-65 HRC?
9CrSi Hardened 63-65 HRC is 9CrSi heat treated to Hardened 63-65 HRC — treat only as an intermediate state straight from the 860–880 °C oil quench; temper immediately to relieve quenching stress, otherwise cracking is likely at 64 HRC. 9CrSi Hardened 63-65 HRC has a yield strength of 2,050 MPa (297 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 210 GPa (30.5 Msi). 9CrSi Hardened 63-65 HRC 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). Annealed is the default condition FabDigit quotes; Hardened 63-65 HRC is available on request or by drawing note.
Advantages
- High strength — 2,050 MPa (297 ksi), better than 100% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited ductility — 0.5%, worse than 100% of steel grades
- Difficult to machine — 5/100, worse than 100% of steel grades
- Difficult to weld — 3/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Limited service temperature — 150°C (302 °F), worse than 99% of steel grades
9CrSi Hardened 63-65 HRC properties
Typical room-temperature values for 9CrSi Hardened 63-65 HRC; 21 are specific to this condition. Other listed values are 9CrSi reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
9CrSi Hardened 63-65 HRC 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 Hardened 63-65 HRC has a yield strength of 2,050 MPa (297 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
9CrSi Hardened 63-65 HRC is rated for continuous service to 150°C (302 °F). It conducts heat at 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 84% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
9CrSi Hardened 63-65 HRC conducts electricity at 5.7 % IACS, worse than 80% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 9CrSi Hardened 63-65 HRC 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 Hardened 63-65 HRC's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (3/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 9CrSi Hardened 63-65 HRC
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 Hardened 63-65 HRC — frequently asked
What is 9CrSi Hardened 63-65 HRC used for?
9CrSi Hardened 63-65 HRC 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 Hardened 63-65 HRC?
9CrSi Hardened 63-65 HRC has a typical yield strength of 2,050 MPa (297 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 9CrSi Hardened 63-65 HRC easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% 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 Hardened 63-65 HRC be welded?
Not readily — weldability is rated not recommended (3/100). 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 Hardened 63-65 HRC?
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 Hardened 63-65 HRC 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 Hardened 63-65 HRC?
9CrSi Hardened 63-65 HRC is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 9CrSi Hardened 63-65 HRC?
Yes — 9CrSi Hardened 63-65 HRC is available for CNC machining; every part is priced by an engineer rather than instantly. 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.