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Steel SNCM431-CD (Cold drawn)

Supply condition

JIS SNCM431

Pick annealed and cold-drawn bar for accurate small diameters and bright surface ready for direct machining, accepting 12% elongation and residual stress from drawing.

Budget cost $

Values for the CD condition

Other SNCM431 tempers and conditions

SNCM431 is listed in 9 conditions; see the grade overview at SNCM431.

Compare all 9 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Solution annealed
Pick the full anneal at 820–860 °C with furnace cooling for post-forging softening, heavy machining or as stock before re-hardening, giving the lowest 200 HB and best machinability.47069023200 HB—
Hot rolled
Choose as-rolled bar as the lowest-cost delivery form for blanks that will be quenched and tempered or forged later; properties scatter around 520 MPa yield and 235 HB.5208001921 HRC8 % IACS
Normalized
Use normalizing at 870–900 °C with air cooling to refine and homogenize forged structure as an intermediate or delivery state, stronger than annealed at 570 MPa yield yet still machinable.5708502024 HRC—
CDThis page
Cold drawn
Pick annealed and cold-drawn bar for accurate small diameters and bright surface ready for direct machining, accepting 12% elongation and residual stress from drawing.6507801220 HRC8 % IACS
Stress relieved
Apply stress relief at 550–650 °C after welding or rough machining to stabilize dimensions while keeping essentially quench-and-temper hardness at 265 HB.7308802026 HRC7.8 % IACS
QTDefault
Quenched and tempered
Use the common delivery state, oil quenched at 820–870 °C and tempered at 570–670 °C to the 830 MPa class, for shafts, gear blanks and rods needing strength with 20% elongation.7609002028 HRC—
tempered ~590–620 °C
Choose the 28–32 HRC temper at 590–620 °C as the general medium-strength setting for mid-section drive shafts, balancing 850 MPa yield, 18% elongation and machinability.8509901830 HRC—
tempered ~540–580 °C
Pick tempering at 540–580 °C to 32–36 HRC for shafts and fasteners under higher contact or bending stress; yield reaches 980 MPa with slightly reduced impact toughness.9801,1101634 HRC—
tempered ~480–520 °C
Use the 480–520 °C temper to 36–40 HRC for small high-strength parts such as pins and high-tensile bolts; toughness and machinability drop and hydrogen embrittlement must be controlled.1,1201,2501338 HRC—

What is SNCM431-CD?

SNCM431-CD is SNCM431 supplied in the CD condition — pick annealed and cold-drawn bar for accurate small diameters and bright surface ready for direct machining, accepting 12% elongation and residual stress from drawing. SNCM431-CD has a yield strength of 650 MPa (94.3 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 79% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). SNCM431-CD 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). QT is the default condition FabDigit quotes; CD is available on request or by drawing note.

Advantages

  • High strength — 650 MPa (94.3 ksi), better than 79% of steel grades

Limitations

  • Limited ductility — 12%, worse than 84% of steel grades

SNCM431-CD properties

Typical room-temperature values for SNCM431-CD; 23 are specific to this condition. Other listed values are SNCM431 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

SNCM431-CD 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).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,420°C2,588 °F
Liquidus Temperature1,490°C2,714 °F

Mechanical16

SNCM431-CD has a yield strength of 650 MPa (94.3 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 79% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).

Elastic (Young's) Modulus205 GPa29.7 Msi
Shear Modulus80 GPa11.6 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)780 MPa113 ksi
Yield Strength (0.2% offset)650 MPa94.3 ksi
Elongation at Break12%
Reduction in Area40%
Compressive Strength670 MPa97.2 ksi
Shear Strength485 MPa70.3 ksi
Fatigue Strength (Endurance Limit)350 MPa50.8 ksi
Fracture Toughness (K_IC)95 MPa·√m86.5 ksi·√in
Charpy V-Notch Impact (RT)30 J22.1 ft·lbf
Hardness, Brinell230 HB
Hardness, Rockwell C20 HRC
Hardness, Vickers242 HV

Thermal6

SNCM431-CD is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).

Thermal Conductivity44 W/m·K25.4 BTU/hr·ft·°F
Specific Heat Capacity470 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12.3 µm/m·K6.8 µin/in·°F
Latent Heat of Fusion250 J/g107 BTU/lb
Max Service Temperature (continuous)350°C662 °F
Min Service Temperature-40°C-40 °F

Electrical3

SNCM431-CD conducts electricity at 8 % IACS, better than 55% of steel grades.

Electrical Conductivity8 % IACS
Electrical Resistivity2.15×10⁻⁷ Ω·m8.46 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.61 V
Corrosion ResistanceNot recommended12/100
Chemical Resistance Summary—

Sustainability4

Producing a kilogram of SNCM431-CD takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.

Embodied Energy (primary production)30 MJ/kg12,898 BTU/lb
Embodied Carbon (primary production)2.3 kg CO₂/kg
Embodied Water60 L/kg7.2 gal/lb
Typical Recycled Content30%

Manufacturability7

SNCM431-CD's machinability is good (60/100, better than 83% of steel grades); weldability fair (40/100); formability poor (25/100).

MachinabilityGood60/100
Machinability Rating (AISI 1212 = 100 %)65%
WeldabilityFair40/100
Formability (cold)Poor25/100
CastabilityPoor25/100
Brazeability / SolderabilityGood55/100
PolishabilityGood60/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with SNCM431-CD

Is SNCM431 easy to machine?

Annealed and normalized material machines most easily (about 55-65% of AISI 1212). Above 30 HRC after quench and temper, use coated carbide with lower speed, higher feed and generous coolant.

Can SNCM431 be welded?

Carbon equivalent is about 0.7-0.8, so use 200-300 °C preheat and low-hydrogen consumables, followed by a 580-650 °C temper to avoid martensitic cracking.

Can SNCM431 be formed, bent or molded?

Forge at approximately 1100-1200 °C with finishing temperature no lower than 850 °C. Cold forming is restricted to light bending and upsetting in the annealed condition.

What surface finishes work on SNCM431?

No inherent corrosion resistance — apply black oxide, phosphate, zinc or chrome plating, or paint. Electroplated parts in the high-strength tempers require hydrogen bake-out at 190-210 °C for 4-24 h.

SNCM431 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.

ElementSpec limit (wt %)Nominal
CJIS G40530.27 – 0.350.31
Si0.15 – 0.350.25
Mn0.6 – 0.90.75
P≤ 0.03—
S≤ 0.03—
Ni1.6 – 21.8
Cr0.6 – 10.8
Mo0.15 – 0.30.22
Curesidual max≤ 0.3—
Febalance—

SNCM431-CD — frequently asked

What is SNCM431-CD used for?

SNCM431-CD is typically used for shafts, structural bolts and pressure vessel components. In short: balanced strength and toughness; through-hardening Ni-Cr-Mo bar; weldable with preheat.

What is the yield strength of SNCM431-CD?

SNCM431-CD has a typical yield strength of 650 MPa (94.3 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 79% of steel grades. Strength varies by condition: see the 9 listed tempers.

Is SNCM431-CD easy to machine?

Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Annealed and normalized material machines most easily (about 55-65% of AISI 1212). Above 30 HRC after quench and temper, use coated carbide with lower speed, higher feed and generous coolant.

Can SNCM431-CD be welded?

With care — weldability is rated fair (40/100). Carbon equivalent is about 0.7-0.8, so use 200-300 °C preheat and low-hydrogen consumables, followed by a 580-650 °C temper to avoid martensitic cracking.

What surface finishes work on SNCM431-CD?

No inherent corrosion resistance — apply black oxide, phosphate, zinc or chrome plating, or paint. Electroplated parts in the high-strength tempers require hydrogen bake-out at 190-210 °C for 4-24 h.

Can SNCM431-CD be formed, bent or molded?

Forge at approximately 1100-1200 °C with finishing temperature no lower than 850 °C. Cold forming is restricted to light bending and upsetting in the annealed condition.

What is the maximum service temperature of SNCM431-CD?

SNCM431-CD is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between SNCM431-QT and SNCM431-A?

QT is the default condition — use the common delivery state, oil quenched at 820–870 °C and tempered at 570–670 °C to the 830 MPa class, for shafts, gear blanks and rods needing strength with 20% elongation. A: pick the full anneal at 820–860 °C with furnace cooling for post-forging softening, heavy machining or as stock before re-hardening, giving the lowest 200 HB and best machinability. Yield strength is 760 MPa in QT versus 470 MPa in A.

Sources

  1. SAE J404 Chemical Compositions of SAE Alloy Steels (8630) — SAE International (2021)
  2. ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
  3. ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)

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.