Steel 43CrMo4
EN 43CrMo4
43CrMo4 (1.3563, comparable to 4142) is a chromium-molybdenum through-hardening steel with carbon raised slightly above 42CrMo4, optimized for induction hardening so a hard surface can be produced over a tough quenched-and-tempered core.
Reference datasheet — 43CrMo4 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 +QT condition
43CrMo4 tempers and conditions
43CrMo4 is supplied in 12 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Treated for improved cold shearability | Softened/structure-conditioned bar so coils and bars can be cold-sheared into fastener or forging blanks without cracking. | 390 | 620 | 22 | 200 HB | — |
Annealed | Softest supply condition for heavy machining, deep drilling or cold forming before final hardening. | 420 | 660 | 20 | 215 HB | — |
Specified hardenability | Order this when the Jominy end-quench band must be guaranteed for reproducible induction or through hardening of a given section. | 430 | 660 | 18 | 58 HRC | 7.7 % IACS |
Treated to ferrite–pearlite structure with specified hardness range | Bar supplied in a controlled hardness window for consistent automatic-lathe machining. | 450 | 720 | 18 | 17 HRC | 8 % IACS |
Normalized | Refined, uniform ferrite-bainite structure for stock to be re-hardened or for moderate-duty parts. | 530 | 830 | 16 | 24 HRC | — |
Cold drawn | Close-tolerance bright bar for parts machined with minimal stock removal; strength raised by drawing strain. | 680 | 850 | 9 | 24 HRC | 7.5 % IACS |
+QT | Same treatment on larger bar/forging where mass effect lowers core strength. | 720 | 1,000 | 14 | 31 HRC | — |
tempered for toughness | Pick when impact toughness and machinability matter more than peak strength (oilfield, heavy shafts). | 790 | 960 | 16 | 30 HRC | — |
Nitrided / nitrocarburised over Q&T | Low-distortion thin case for wear and fretting resistance with a slight corrosion improvement. | 820 | 1,050 | 10 | 58 HRC | 7.5 % IACS |
+QTDefault Quenched and tempered | Standard high-strength delivery condition for shafts, gears and machine parts in medium sections. | 850 | 1,100 | 13 | 35 HRC | — |
Induction (surface) hardened over Q&T core | The main reason this grade exists — hard 1–5 mm case on journals, splines and tracks with a tough tempered core. | 850 | 1,100 | 12 | 56 HRC | — |
tempered for strength | Higher-strength temper for gears and highly loaded shafts that will not see severe impact. | 1,030 | 1,180 | 12 | 36 HRC | — |
What is 43CrMo4?
43CrMo4 (1.3563, comparable to 4142) is a chromium-molybdenum through-hardening steel with carbon raised slightly above 42CrMo4, optimized for induction hardening so a hard surface can be produced over a tough quenched-and-tempered core. Engineers use it for shafts, gears and highly loaded fasteners; it is stocked as bar and forging stock in +A, +N, +FP, +S, +H, +QT, induction-hardened and nitrided conditions. Typical +QT properties are 850 MPa yield, 1100 MPa tensile, 13 % elongation and 330 HB (35 HRC), with service to 400 °C. Weldability and cold formability are poor, and there is no corrosion resistance, so protective coatings are required. 43CrMo4 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). 43CrMo4 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
What is 43CrMo4 used for?
- induction-hardened shafts
- gears
- bearing races
- axles
- high-strength fasteners
Advantages
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 13%, worse than 78% of steel grades
43CrMo4 properties
Typical room-temperature values for 43CrMo4-+QT; bars are the position among steel grades.
Physical3
43CrMo4 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).
Mechanical16
43CrMo4 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
43CrMo4 is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
43CrMo4 conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 43CrMo4 takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 35%.
Manufacturability7
43CrMo4's machinability is fair (48/100, worse than 57% of steel grades); weldability fair (35/100); formability poor (25/100).
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. 43CrMo4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 43CrMo4
Is 43CrMo4 easy to machine?
Machine in +A/+FP (≈200–240 HB) with carbide at 120–180 m/min; in +QT above 300 HB drop speed ~40 % and use rigid setups and coated inserts.
Can 43CrMo4 be welded?
Weldable only with care: preheat 300–350 °C, low-hydrogen consumables, interpass control, and temper/stress relieve at 550–650 °C immediately after welding.
Can 43CrMo4 be formed, bent or molded?
Hot forge 1100→850 °C then slow cool or normalize; cold forming/shearing only in +A or +S condition.
43CrMo4 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 |
|---|---|---|
| Chigher than 42CrMo4 to suit induction hardening | 0.4 – 0.47 | 0.43 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| Slower S (≤0.005) for +QT high-toughness variants | ≤ 0.04 | 0.02 |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.15 – 0.3 | 0.22 |
| Niresidual | ≤ 0.4 | 0.15 |
| Curesidual | ≤ 0.3 | 0.15 |
| Fe | balance |
What surface finishes work on 43CrMo4?
No anodizing — protect with black oxide, manganese phosphate, zinc or hard-chrome plating; bake after plating to avoid hydrogen embrittlement; nitriding and induction hardening give the best wear surfaces.
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 43CrMo4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.3563
- Similar grades
- 4142
How much does 43CrMo4 cost?
43CrMo4 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.
43CrMo4 — frequently asked
What is 43CrMo4 used for?
43CrMo4 is typically used for induction-hardened shafts, gears, bearing races, axles and high-strength fasteners. In short: induction-hardening 42CrMo4 variant; deep through-hardening strength; hard surface, tough core.
What is the yield strength of 43CrMo4?
43CrMo4 has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is 43CrMo4 easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machine in +A/+FP (≈200–240 HB) with carbide at 120–180 m/min; in +QT above 300 HB drop speed ~40 % and use rigid setups and coated inserts.
Can 43CrMo4 be welded?
With care — weldability is rated fair (35/100). Weldable only with care: preheat 300–350 °C, low-hydrogen consumables, interpass control, and temper/stress relieve at 550–650 °C immediately after welding.
What surface finishes work on 43CrMo4?
No anodizing — protect with black oxide, manganese phosphate, zinc or hard-chrome plating; bake after plating to avoid hydrogen embrittlement; nitriding and induction hardening give the best wear surfaces.
Can 43CrMo4 be formed, bent or molded?
Hot forge 1100→850 °C then slow cool or normalize; cold forming/shearing only in +A or +S condition.
What is the maximum service temperature of 43CrMo4?
43CrMo4 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 43CrMo4 +QT and 43CrMo4-NIT?
+QT is the default condition — standard high-strength delivery condition for shafts, gears and machine parts in medium sections. NIT: low-distortion thin case for wear and fretting resistance with a slight corrosion improvement. Yield strength is 850 MPa in +QT versus 820 MPa in NIT.
How much does 43CrMo4 cost?
43CrMo4 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
- EN 10083-3 Steels for quenching and tempering — Alloy steels — CEN (2006)
- EN 10084 / EN 10250-3 (bar and open-die forged product conditions) — CEN (2019)
- GB/T 3077 (42CrMo class) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Cr-Mo through-hardening steel bar datasheets (Ovako, Böhler, Saarstahl 42CrMo4/43CrMo4) — various producers (2023)
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.