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Steel SUP10 Normalized

Heat-treated state

GB SUP10 · AISI/SAE 6150 · EN 50CrV4, 50CrVA

Use to homogenise forgings and refine grain before hardening, or where moderate strength suffices.

CNC machiningSheet metalStandard cost $$

Values for the Normalized condition

Other SUP10 tempers and conditions

SUP10 is listed in 6 conditions; see the grade overview at SUP10.

Compare all 6 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
AnnealedDefault
soft/spheroidize annealed bar and coil for machining and forming
Stock condition for machining, cold forming and pre-heat-treat blanks before quench and temper.48078020210 HB—
as-rolled bar, flat and coil
Cheapest mill condition for leaf-spring flats and forging stock that will be heat treated later.5609001425 HRC7.5 % IACS
NormalizedThis page
austenitised and air cooled, refined grain
Use to homogenise forgings and refine grain before hardening, or where moderate strength suffices.6601,0001331 HRC7.5 % IACS
cold drawn / peeled-ground annealed bar and wire
Choose for close-tolerance bar, torsion-bar and wire blanks needing good surface before hardening.800950928 HRC7.4 % IACS
Higher-temper condition for toughness-critical torsion bars and…
Use where fatigue with impact loading matters more than peak stress (stabiliser bars, heavy leaf springs).1,1201,2501140 HRC7.2 % IACS
Quenched and tempered
Standard spring condition: highest usable strength with adequate toughness for leaf, coil and torsion springs.1,3001,450944 HRC—

What is SUP10 Normalized?

SUP10 Normalized is SUP10 heat treated to Normalized — use to homogenise forgings and refine grain before hardening, or where moderate strength suffices. SUP10 Normalized has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of steel grades. Elongation at break is 13% and the elastic modulus is 206 GPa (29.9 Msi). SUP10 Normalized 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). Annealed is the default condition FabDigit quotes; Normalized is available on request or by drawing note.

Advantages

  • High strength — 660 MPa (95.7 ksi), better than 80% of steel grades

Limitations

  • Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
  • Limited ductility — 13%, worse than 78% of steel grades
  • Difficult to weld — 25/100, worse than 77% of steel grades

SUP10 Normalized properties

Typical room-temperature values for SUP10 Normalized; 22 are specific to this condition. Other listed values are SUP10 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

SUP10 Normalized 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

Mechanical14

SUP10 Normalized has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of steel grades. Elongation at break is 13% and the elastic modulus is 206 GPa (29.9 Msi).

Elastic (Young's) Modulus206 GPa29.9 Msi
Shear Modulus79 GPa11.5 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)1,000 MPa145 ksi
Yield Strength (0.2% offset)660 MPa95.7 ksi
Elongation at Break13%
Reduction in Area35%
Shear Strength600 MPa87 ksi
Fatigue Strength (Endurance Limit)450 MPa65.3 ksi
Charpy V-Notch Impact (RT)26 J19.2 ft·lbf
Hardness, Brinell300 HB
Hardness, Rockwell B94 HRB
Hardness, Vickers315 HV

Thermal6

SUP10 Normalized is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 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)12.5 µm/m·K6.9 µin/in·°F
Latent Heat of Fusion250 J/g107 BTU/lb
Max Service Temperature (continuous)200°C392 °F
Min Service Temperature-40°C-40 °F

Electrical3

SUP10 Normalized conducts electricity at 7.5 % IACS, worse than 67% of steel grades.

Electrical Conductivity7.5 % IACS
Electrical Resistivity2.3×10⁻⁷ Ω·m9.06 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

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

Galvanic Potential (seawater, vs SCE)-0.62 V
Corrosion ResistanceNot recommended12/100
Chemical Resistance SummaryRusts readily in humid air and water; no resistance to acids or chlorides. Requires phosphating, oil, paint, zinc plating or shot-peen plus coating; avoid hydrogen-charging pickling/plating on hardened springs (delayed fracture).

Sustainability4

Producing a kilogram of SUP10 Normalized takes about 30 MJ of energy and emits 2.2 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)2.2 kg CO₂/kg
Embodied Water60 L/kg7.2 gal/lb
Typical Recycled Content30%

Manufacturability7

SUP10 Normalized's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (25/100); formability poor (25/100).

MachinabilityFair45/100
Machinability Rating (AISI 1212 = 100 %)45%
WeldabilityPoor25/100
Formability (cold)Poor25/100
CastabilityPoor25/100
Brazeability / SolderabilityFair50/100
PolishabilityGood60/100

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

Working with SUP10 Normalized

Is SUP10 easy to machine?

Machine in the annealed condition (~55 % of 1212) with rigid setups and carbide at moderate speed; above 40 HRC switch to grinding, CBN or EDM.

Can SUP10 be welded?

Effectively not weldable in the hardened state — high carbon equivalent causes cracking; if unavoidable, preheat 300–350 °C, low-hydrogen consumables and re-quench/temper the whole part.

Can SUP10 be formed, bent or molded?

Cold form or coil only when annealed or as oil-tempered wire; hot forge 1050–1150 °C, finish above 900 °C, slow cool, then harden from 830–870 °C in oil and temper 400–500 °C.

What surface finishes work on SUP10?

No corrosion resistance of its own: shot-peen springs then phosphate + oil, powder coat or paint; avoid acid pickling and electroplating on hardened parts unless baked to relieve hydrogen.

SUP10 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 G4801 SUP100.47 – 0.550.51
Si0.15 – 0.350.25
Mn0.65 – 0.950.8
P≤ 0.03—
S≤ 0.03—
Cr0.8 – 1.10.95
Vgrain refinement, relaxation resistance0.15 – 0.250.2
Cu≤ 0.3—
Febalance—

SUP10 Normalized — frequently asked

What is SUP10 Normalized used for?

SUP10 Normalized is typically used for coil springs, leaf springs and springs. In short: heavy-duty spring bar.

What is the yield strength of SUP10 Normalized?

SUP10 Normalized has a typical yield strength of 660 MPa (95.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of steel grades. Strength varies by condition: see the 6 listed tempers.

Is SUP10 Normalized easy to machine?

Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed condition (~55 % of 1212) with rigid setups and carbide at moderate speed; above 40 HRC switch to grinding, CBN or EDM.

Can SUP10 Normalized be welded?

Not readily — weldability is rated poor (25/100). Effectively not weldable in the hardened state — high carbon equivalent causes cracking; if unavoidable, preheat 300–350 °C, low-hydrogen consumables and re-quench/temper the whole part.

What surface finishes work on SUP10 Normalized?

No corrosion resistance of its own: shot-peen springs then phosphate + oil, powder coat or paint; avoid acid pickling and electroplating on hardened parts unless baked to relieve hydrogen.

Can SUP10 Normalized be formed, bent or molded?

Cold form or coil only when annealed or as oil-tempered wire; hot forge 1050–1150 °C, finish above 900 °C, slow cool, then harden from 830–870 °C in oil and temper 400–500 °C.

What is the maximum service temperature of SUP10 Normalized?

SUP10 Normalized is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Can FabDigit make parts in SUP10 Normalized?

Yes — SUP10 Normalized 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

  1. JIS G 4801 Spring steels — Japanese Standards Association (2021)
  2. GB/T 1222 (50CrVA) — SAC (2016)
  3. SAE J404 / ASTM A231 (6150 Cr-V spring steel) — SAE / ASTM (2020)
  4. ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
  5. Machinery's Handbook (machinability ratings, spring design) — Industrial Press (2020)
  6. Mysteel / 1688 spring steel bar spot quotations (2026)

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.