Steel 4817-HR (Hot rolled)
Supply condition
AISI/SAE 4817 · UNS G48170
Cheapest mill condition for rough forging or machining stock that will be annealed before carburizing.
Values for the HR condition
Other 4817 tempers and conditions
4817 is listed in 6 conditions; see the grade overview at 4817.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HRThis page Hot rolled | Cheapest mill condition for rough forging or machining stock that will be annealed before carburizing. | 440 | 720 | 22 | 15 HRC | 6.9 % IACS |
ADefault Solution annealed | Standard stocking and machining condition prior to carburizing; softest, most stable structure. | 450 | 690 | 24 | 195 HB | — |
Normalized | Use to refine forging grain and give a uniform core structure before carburizing; slightly stronger and tougher than annealed. | 490 | 760 | 23 | 17 HRC | 6.9 % IACS |
Cold drawn | Pick for close-tolerance small-diameter bar and better surface finish where core strength before case hardening is helpful. | 660 | 790 | 13 | 20 HRC | 6.9 % IACS |
Carburized & hardened | The intended service condition: hard wear-resistant case on a tough high-nickel core for gears, pinions and races. | 950 | 1,200 | 12 | 60 HRC | — |
Q&T | For through-hardened parts (fasteners, shafts) where a carburized case is not wanted but very high core toughness is. | 1,000 | 1,240 | 13 | 39 HRC | — |
What is 4817-HR?
4817-HR is 4817 supplied in the HR condition — cheapest mill condition for rough forging or machining stock that will be annealed before carburizing. 4817-HR has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 50% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi). 4817-HR has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
4817-HR properties
Typical room-temperature values for 4817-HR; 23 are specific to this condition. Other listed values are 4817 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4817-HR has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
4817-HR has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 50% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4817-HR is rated for continuous service to 200°C (392 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical2
4817-HR has an electrical resistivity of 2.5×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of 4817-HR takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
4817-HR's machinability is fair (40/100, worse than 77% of steel grades); weldability fair (35/100); formability fair (42/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4817-HR
Is 4817 easy to machine?
Machine in the annealed condition with sharp, positive-rake carbide at moderate speeds and generous coolant; the nickel makes chips gummy and work-hardening at the cut edge, so avoid dwelling and finish before carburizing.
Can 4817 be welded?
Weldable only in the un-carburized state with low-hydrogen consumables, 200–300 °C preheat and immediate stress relief; do not weld carburized surfaces — the high-carbon case cracks.
Can 4817 be formed, bent or molded?
Hot forge 1090–1200 °C and finish above 900 °C, then normalize and anneal; cold forming is limited to mild bending or heading of annealed small-diameter bar.
What surface finishes work on 4817?
Grind the case after hardening for size and finish (allow 0.1–0.3 mm stock); protect with oil, phosphate, black oxide or zinc/Cr plating — bake plated parts to avoid hydrogen embrittlement.
4817 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 |
|---|---|---|
| Cone step above 4815, below 4820 | 0.15 – 0.2 | 0.17 |
| Mn | 0.4 – 0.6 | 0.5 |
| Si | 0.15 – 0.35 | 0.25 |
| Ni | 3.25 – 3.75 | 3.5 |
| Mo | 0.2 – 0.3 | 0.25 |
| Pmax, bar/billet | ≤ 0.04 | — |
| Smax, bar/billet | ≤ 0.04 | — |
| Fe | balance | — |
4817-HR — frequently asked
What is 4817-HR used for?
4817-HR is typically used for heavy-duty gears, shafts and aircraft components. In short: high-nickel carburizing steel; tough core in heavy sections; harder to machine than 8620.
What is the yield strength of 4817-HR?
4817-HR has a typical yield strength of 440 MPa (63.8 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 50% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 4817-HR easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine in the annealed condition with sharp, positive-rake carbide at moderate speeds and generous coolant; the nickel makes chips gummy and work-hardening at the cut edge, so avoid dwelling and finish before carburizing.
Can 4817-HR be welded?
With care — weldability is rated fair (35/100). Weldable only in the un-carburized state with low-hydrogen consumables, 200–300 °C preheat and immediate stress relief; do not weld carburized surfaces — the high-carbon case cracks.
What surface finishes work on 4817-HR?
Grind the case after hardening for size and finish (allow 0.1–0.3 mm stock); protect with oil, phosphate, black oxide or zinc/Cr plating — bake plated parts to avoid hydrogen embrittlement.
Can 4817-HR be formed, bent or molded?
Hot forge 1090–1200 °C and finish above 900 °C, then normalize and anneal; cold forming is limited to mild bending or heading of annealed small-diameter bar.
What is the maximum service temperature of 4817-HR?
4817-HR is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4817-A and 4817 QT-DH?
A is the default condition — standard stocking and machining condition prior to carburizing; softest, most stable structure. QT-DH: for through-hardened parts (fasteners, shafts) where a carburized case is not wanted but very high core toughness is. Yield strength is 450 MPa in A versus 1,000 MPa in QT-DH.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals and Processes (carburizing) — ASM International (2013)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
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.