Steel 4023-HR (Hot rolled)
Supply condition
AISI/SAE 4023 · UNS G40230
Cheapest bar condition for parts that will be machined and then carburized or heat treated.
Values for the HR condition
Other 4023 tempers and conditions
4023 is listed in 7 conditions; see the grade overview at 4023.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition; choose for heavy cold forming, deep drilling or before carburizing. | 290 | 448 | 28 | 137 HB | — |
HRThis page Hot rolled | Cheapest bar condition for parts that will be machined and then carburized or heat treated. | 315 | 490 | 25 | 143 HB | — |
Normalized | Uniform fine grain and predictable machining response for forgings before carburizing. | 345 | 520 | 25 | 156 HB | — |
Q&T | Tough medium-strength condition for shafts and small forgings not requiring a hard case. | 450 | 600 | 24 | 179 HB | — |
CDDefault Cold drawn | Most commonly stocked bar: tight tolerance, bright finish, higher yield strength for as-machined parts. | 470 | 552 | 18 | 163 HB | — |
Q&T | Direct hardening of thin sections where a carburized case is not required; limited hardenability above ~25 mm. | 520 | 720 | 17 | 19 HRC | — |
Carburized, quenched & tempered | The intended service condition: hard wear-resistant case over a tough, moderately strong core for gears and pins. | 560 | 780 | 15 | 60 HRC | — |
What is 4023-HR?
4023-HR is 4023 supplied in the HR condition — cheapest bar condition for parts that will be machined and then carburized or heat treated. 4023-HR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 82% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi). 4023-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). CD is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Forms and bends easily — 65/100, better than 81% of steel grades
- Readily welded — 78/100, better than 78% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- Low strength — 315 MPa (45.7 ksi), worse than 82% of steel grades
4023-HR properties
Typical room-temperature values for 4023-HR; 12 are specific to this condition. Other listed values are 4023 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4023-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
4023-HR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 82% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4023-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
4023-HR conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4023-HR takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
4023-HR's machinability is good (58/100, better than 75% of steel grades); weldability very good (78/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4023-HR
Is 4023 easy to machine?
Machines like a soft low-alloy steel (~70 % of 1212); best surface finish in the normalized or cold-drawn condition, use sharp positive-rake carbide and good coolant to avoid built-up edge.
Can 4023 be welded?
Good weldability at 0.2 % C with low Mo; preheat 100–200 °C on thick sections, use low-hydrogen E70XX/ER70S-x consumables, and never weld after carburizing.
Can 4023 be formed, bent or molded?
Cold heads and bends well when annealed; hot forge 1100–1200 °C and normalize afterwards to refine grain before carburizing.
What surface finishes work on 4023?
Not corrosion resistant — specify black oxide, phosphate + oil, zinc or nickel plating; bake after plating to prevent hydrogen embrittlement of hardened cases.
4023 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 | 0.2 – 0.25 | 0.23 |
| Mn | 0.7 – 0.9 | 0.8 |
| Si | 0.15 – 0.35 | 0.25 |
| Mo | 0.2 – 0.3 | 0.25 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Fe | balance | — |
4023-HR — frequently asked
What is 4023-HR used for?
4023-HR is typically used for shafts, couplings, connecting rods and gears. In short: weldable 40xx carburizing grade; balanced strength and toughness; common forging stock.
What is the yield strength of 4023-HR?
4023-HR has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 82% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 4023-HR easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines like a soft low-alloy steel (~70 % of 1212); best surface finish in the normalized or cold-drawn condition, use sharp positive-rake carbide and good coolant to avoid built-up edge.
Can 4023-HR be welded?
Yes — weldability is rated very good (78/100). Good weldability at 0.2 % C with low Mo; preheat 100–200 °C on thick sections, use low-hydrogen E70XX/ER70S-x consumables, and never weld after carburizing.
What surface finishes work on 4023-HR?
Not corrosion resistant — specify black oxide, phosphate + oil, zinc or nickel plating; bake after plating to prevent hydrogen embrittlement of hardened cases.
Can 4023-HR be formed, bent or molded?
Cold heads and bends well when annealed; hot forge 1100–1200 °C and normalize afterwards to refine grain before carburizing.
What is the maximum service temperature of 4023-HR?
4023-HR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4023-CD and 4023-A?
CD is the default condition — most commonly stocked bar: tight tolerance, bright finish, higher yield strength for as-machined parts. A: softest condition; choose for heavy cold forming, deep drilling or before carburizing. Yield strength is 470 MPa in CD versus 290 MPa in A.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (Carburizing of Alloy Steels) — ASM International (1991)
- Machining Data Handbook — Metcut Research Associates (1980)
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.