Stainless Steel 7Cr17-HR (Hot rolled)
Supply condition
EN 7Cr17
Mill supply form for thick bar and plate that will be machined and heat treated by the user.
Values for the HR condition
Other 7Cr17 tempers and conditions
7Cr17 is listed in 7 conditions; see the grade overview at 7Cr17.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard supply condition for machining, blanking and blade grinding before hardening. | 415 | 740 | 20 | 220 HB | — |
HRThis page Hot rolled | Mill supply form for thick bar and plate that will be machined and heat treated by the user. | 430 | 760 | 18 | 20 HRC | 2.9 % IACS |
Cold rolled, half hard strip | Work-hardened strip for stamped blanks and springy parts that will be hardened later. | 750 | 950 | 6 | 30 HRC | 2.9 % IACS |
Q&T ~44–48 HRC | Tougher setting for scissors, shear blades and mechanical parts where chipping must be avoided. | 1,250 | 1,450 | 8 | 46 HRC | — |
Q&T 50–53 HRC | Common kitchen-knife and kitchenware hardness: good balance of edge holding and toughness. | 1,500 | 1,700 | 6 | 52 HRC | — |
Q&T 54–57 HRC | Maximum practical hardness for 7Cr17: best edge retention, lowest toughness and corrosion margin. | 1,650 | 1,850 | 4 | 56 HRC | — |
Hardened + sub-zero + temper | Adds a −75 °C sub-zero step to convert retained austenite for maximum hardness and dimensional stability. | 1,700 | 1,900 | 3 | 57 HRC | 2.8 % IACS |
What is 7Cr17-HR?
7Cr17-HR is 7Cr17 supplied in the HR condition — mill supply form for thick bar and plate that will be machined and heat treated by the user. 7Cr17-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi). 7Cr17-HR has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,370°C (2,498 °F). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Low embodied carbon — 3.5 kg CO₂/kg, better than 88% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Difficult to weld — 22/100, worse than 94% of stainless steel grades
- Low fracture toughness — 58 MPa·√m (52.8 ksi·√in), worse than 90% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Limited ductility — 18%, worse than 83% of stainless steel grades
7Cr17-HR properties
Typical room-temperature values for 7Cr17-HR; 23 are specific to this condition. Other listed values are 7Cr17 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
7Cr17-HR has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
7Cr17-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
7Cr17-HR is rated for continuous service to 425°C (797 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.2 µm/m·K (5.67 µin/in·°F).
Electrical3
7Cr17-HR conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 7Cr17-HR takes about 45 MJ of energy and emits 3.5 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 50%.
Manufacturability8
7Cr17-HR's machinability is fair (42/100, better than 79% of stainless steel grades); weldability poor (22/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7Cr17-HR
Is 7Cr17 easy to machine?
Machine only in the annealed state with sharp carbide tooling, rigid setups and generous coolant; hardened parts require grinding, EDM or CBN.
Can 7Cr17 be welded?
Poor weldability — 0.7 %C martensitic; if unavoidable preheat 200–300 °C, use 309/410NiMo filler and temper immediately after welding.
Can 7Cr17 be formed, bent or molded?
Blank and lightly bend only in the annealed condition with generous radii; harden 1010–1065 °C, oil or air quench, temper below 200 °C or above 550 °C only with corrosion penalty — avoid 400–550 °C.
What surface finishes work on 7Cr17?
Grind, belt and mirror-polish after hardening, then passivate (nitric or citric per ASTM A967); PVD/TiN or chrome plating used on budget cutlery for extra corrosion protection.
7Cr17 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 |
|---|---|---|
| CGB/T 1220 68Cr17 (old 7Cr17) | 0.6 – 0.75 | 0.68 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.5 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 16 – 18 | 17 |
| Mooptional residual | ≤ 0.75 | — |
| Niresidual | ≤ 0.6 | — |
| Fe | balance | — |
7Cr17-HR — frequently asked
What is 7Cr17-HR used for?
7Cr17-HR is typically used for kitchen knives, kitchenware, mechanical fittings and shafts. In short: hardenable budget cutlery steel; low-cost 420-type stainless; poor weldability, good hardenability.
What is the yield strength of 7Cr17-HR?
7Cr17-HR has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 7Cr17-HR easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine only in the annealed state with sharp carbide tooling, rigid setups and generous coolant; hardened parts require grinding, EDM or CBN.
Can 7Cr17-HR be welded?
Not readily — weldability is rated poor (22/100). Poor weldability — 0.7 %C martensitic; if unavoidable preheat 200–300 °C, use 309/410NiMo filler and temper immediately after welding.
What surface finishes work on 7Cr17-HR?
Grind, belt and mirror-polish after hardening, then passivate (nitric or citric per ASTM A967); PVD/TiN or chrome plating used on budget cutlery for extra corrosion protection.
Can 7Cr17-HR be formed, bent or molded?
Blank and lightly bend only in the annealed condition with generous radii; harden 1010–1065 °C, oil or air quench, temper below 200 °C or above 550 °C only with corrosion penalty — avoid 400–550 °C.
What is the maximum service temperature of 7Cr17-HR?
7Cr17-HR is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 7Cr17-A and 7Cr17 QT-CRYO?
A is the default condition — standard supply condition for machining, blanking and blade grinding before hardening. QT-CRYO: adds a −75 °C sub-zero step to convert retained austenite for maximum hardness and dimensional stability. Yield strength is 415 MPa in A versus 1,700 MPa in QT-CRYO.
Sources
- GB/T 1220 (68Cr17 / 7Cr17) — SAC (2007)
- GB/T 4232 / ASTM A276 martensitic stainless bar — SAC / ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels (440A) — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating of Stainless Steels — ASM International (1991)
- ASM Handbook Vol.13B — Corrosion of Stainless Steels — ASM International (2005)
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.