Steel 4023
AISI/SAE 4023 · UNS G40230
4023 is a general-purpose 0.20 % C molybdenum alloy steel (UNS G40230) from the SAE-AISI 40xx family, with Mo added for hardenability and toughness in medium-strength forgings and carburized parts.
Reference datasheet — 4023 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the CD condition
4023 tempers and conditions
4023 is supplied in 7 conditions, soft to hard. CD is the default FabDigit quotes; the values on this page are for it.
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 | — |
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?
4023 is a general-purpose 0.20 % C molybdenum alloy steel (UNS G40230) from the SAE-AISI 40xx family, with Mo added for hardenability and toughness in medium-strength forgings and carburized parts. Default-condition values are roughly 470 MPa yield, 552 MPa tensile, 18 % elongation and 163 HB (84 HRB), and stock is available hot-rolled, annealed, normalized, cold-drawn, quenched-and-tempered (200 or 540 °C) or carburized. It welds well for an alloy steel but has no corrosion resistance and only moderate formability (formability score 50). If machinability matters more than weldability, the resulfurized version 4024 is the direct alternative. 4023 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). 4023 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 57% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is 4023 used for?
- shafts
- couplings
- connecting rods
- gears
Advantages
- Easy to machine — 65/100, better than 93% of steel grades
- Readily welded — 74/100, better than 76% of steel grades
4023 properties
Typical room-temperature values for 4023-CD; bars are the position among steel grades.
Physical3
4023 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 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 57% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4023 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 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 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's machinability is good (65/100, better than 93% of steel grades); weldability very good (74/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 4023 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 4023
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.
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 |
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.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 4023 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G40230
How much does 4023 cost?
4023 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
4023 — frequently asked
What is 4023 used for?
4023 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?
4023 has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 57% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 4023 easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% 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 be welded?
Yes — weldability is rated very good (74/100). 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?
Not corrosion resistant — specify black oxide, phosphate + oil, zinc or nickel plating; bake after plating to prevent hydrogen embrittlement of hardened cases.
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 is the maximum service temperature of 4023?
4023 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.
How much does 4023 cost?
4023 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.