Steel 4330-CR (Cold rolled)
Supply condition
AISI/SAE 4330
Thin flat product with good surface finish, normally re-heat-treated after forming.
Values for the CR condition
Other 4330 tempers and conditions
4330 is listed in 10 conditions; see the grade overview at 4330.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal, softest condition | Pick for maximum machinability and cold working before final quench and temper. | 570 | 760 | 22 | 210 HB | — |
HRDefault Hot rolled | Cheapest mill form for parts that will be heat treated after rough machining or forging. | 600 | 900 | 18 | 26 HRC | 8 % IACS |
Normalized (and optionally tempered) | Uniform fine grain and predictable response before final hardening; used for large forgings. | 650 | 930 | 19 | 28 HRC | 8 % IACS |
Cold drawn | Tight-tolerance small-diameter bar with raised yield strength; no further heat treatment. | 790 | 950 | 12 | 29 HRC | 8 % IACS |
quenched & tempered to 110 ksi (760 MPa) min yield | Lower-strength sour-service oriented class; softest Q&T level with best impact toughness and best HIC/SSC margin. | 800 | 930 | 19 | 26 HRC | — |
CRThis page Cold rolled | Thin flat product with good surface finish, normally re-heat-treated after forming. | 820 | 970 | 10 | 30 HRC | 8 % IACS |
quenched & tempered to 120 ksi (830 MPa) min yield | Balanced oilfield class for tool joints and downhole housings. | 880 | 1,000 | 18 | 30 HRC | — |
quenched & tempered to 130 ksi (900 MPa) min yield | Most common 4330V drilling/aerospace forging class; high strength with still-good CVN. | 960 | 1,080 | 16 | 34 HRC | — |
Quenched and tempered | Standard stocked condition for drill-tool and machined structural parts needing high strength with good toughness. | 965 | 1,100 | 16 | 34 HRC | — |
quenched & tempered to 150 ksi (1035 MPa) min yield | Highest commercial strength level for weight-critical shafts and landing-gear type parts; watch notch sensitivity and hydrogen embrittlement. | 1,100 | 1,240 | 14 | 39 HRC | — |
What is 4330-CR?
4330-CR is 4330 supplied in the CR condition — thin flat product with good surface finish, normally re-heat-treated after forming. 4330-CR has a yield strength of 820 MPa (119 ksi) and a tensile strength of 970 MPa (141 ksi) — stronger than 87% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi). 4330-CR 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). HR is the default condition FabDigit quotes; CR is available on request or by drawing note.
Advantages
- High strength — 820 MPa (119 ksi), better than 87% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited ductility — 10%, worse than 91% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
4330-CR properties
Typical room-temperature values for 4330-CR; 22 are specific to this condition. Other listed values are 4330 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4330-CR 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
4330-CR has a yield strength of 820 MPa (119 ksi) and a tensile strength of 970 MPa (141 ksi) — stronger than 87% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4330-CR is rated for continuous service to 300°C (572 °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
4330-CR conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 4330-CR takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
4330-CR's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (38/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4330-CR
Is 4330 easy to machine?
Machine in the annealed or ≤32 HRC Q&T condition with rigid setups, carbide inserts and moderate speeds; above 38 HRC prefer grinding or ceramic/CBN tooling.
Can 4330 be welded?
Weldable by GTAW/GMAW with low-hydrogen or matching filler, 200–320 °C preheat, controlled interpass and a post-weld temper below the original tempering temperature.
Can 4330 be formed, bent or molded?
Hot forge 1100–1230 °C, finish above 950 °C, then normalize; cold forming is limited to the annealed state with generous radii.
What surface finishes work on 4330?
No anodizing — protect with manganese/zinc phosphate, black oxide, Zn-Ni or Cd plate; bake at ~190 °C after plating to relieve hydrogen, and shot peen fatigue-critical fillets.
4330 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 |
|---|---|---|
| C4330V modified | 0.28 – 0.33 | 0.3 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.2 – 0.35 | 0.28 |
| Ni | 1.65 – 2 | 1.85 |
| Cr | 0.75 – 0.95 | 0.85 |
| Mo | 0.35 – 0.45 | 0.4 |
| Vpresent in 4330V / 4330M; omitted in plain 4330 | 0.05 – 0.1 | 0.07 |
| Pmax; ≤0.010 for VAR aerospace | ≤ 0.02 | — |
| Smax; ≤0.005 for sour service | ≤ 0.02 | — |
| Curesidual max | ≤ 0.35 | — |
| Fe | balance | — |
4330-CR — frequently asked
What is 4330-CR used for?
4330-CR is typically used for drill collars and tool joints, downhole tool bodies, wellhead and valve bodies, aircraft landing gear components, high-strength forgings and heavy-duty shafts and gear blanks. In short: high-strength Cr-Mo-Ni bar.
What is the yield strength of 4330-CR?
4330-CR has a typical yield strength of 820 MPa (119 ksi) and a tensile strength of 970 MPa (141 ksi) — stronger than 87% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 4330-CR easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or ≤32 HRC Q&T condition with rigid setups, carbide inserts and moderate speeds; above 38 HRC prefer grinding or ceramic/CBN tooling.
Can 4330-CR be welded?
With care — weldability is rated fair (38/100). Weldable by GTAW/GMAW with low-hydrogen or matching filler, 200–320 °C preheat, controlled interpass and a post-weld temper below the original tempering temperature.
What surface finishes work on 4330-CR?
No anodizing — protect with manganese/zinc phosphate, black oxide, Zn-Ni or Cd plate; bake at ~190 °C after plating to relieve hydrogen, and shot peen fatigue-critical fillets.
Can 4330-CR be formed, bent or molded?
Hot forge 1100–1230 °C, finish above 950 °C, then normalize; cold forming is limited to the annealed state with generous radii.
What is the maximum service temperature of 4330-CR?
4330-CR is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4330-HR and 4330-CR?
HR is the default condition — cheapest mill form for parts that will be heat treated after rough machining or forging. CR: thin flat product with good surface finish, normally re-heat-treated after forming. Yield strength is 600 MPa in HR versus 820 MPa in CR.
Can FabDigit make parts in 4330-CR?
Yes — 4330-CR is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- AMS 6411 — Steel Bars, Forgings and Tubing 0.95Cr 1.8Ni 0.40Mo 0.08V (4330V) — SAE International (2019)
- 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. 19 — Fatigue and Fracture — ASM International (1996)
- MMPDS-17, low-alloy steel chapters — Battelle/FAA (2022)
- 4330V alloy steel bar and forging data — specialty bar producers (e.g. TimkenSteel/Latrobe-type datasheets) (2021)
- NACE MR0175 / ISO 15156 — Materials for use in H2S-containing environments — NACE/ISO (2015)
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.