Steel 5150
AISI/SAE 5150 · UNS G51500
5150 (UNS G51500) is a medium-carbon chromium alloy steel in the SAE 51xx family, with roughly 0.50 % carbon and chromium added for hardenability and temper resistance.
Values for the HR condition
5150 tempers and conditions
5150 is supplied in 11 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Temper | Softest condition (spheroidize/full anneal) for heavy machining or cold forming before hardening. | 360 | 675 | 22 | 197 HB | — |
HRDefault Hot rolled | As-rolled bar/plate stock for parts that will be machined and then heat treated. | 460 | 800 | 18 | 20 HRC | 8 % IACS |
Heat Treat State | Air cooled from ~870 °C for uniform fine grain and improved machined-part consistency before final hardening. | 530 | 870 | 20.7 | 25 HRC | 8 % IACS |
Cold rolled | Cold-rolled strip/sheet for stamped spring and clip parts, usually finished by hardening and tempering. | 700 | 880 | 10 | 25 HRC | 8 % IACS |
Cold drawn | Cold-drawn bar giving tight size tolerance, better surface finish and higher as-supplied strength than hot rolled. | 760 | 900 | 12 | 27 HRC | 8 % IACS |
Q&T, tempered 650 °C | Tough, lower-strength condition for shafts and fasteners needing impact resistance and easier machining. | 800 | 870 | 20 | 27 HRC | 8 % IACS |
Quenched and tempered | Generic oil-quenched and tempered condition (~540 °C temper) — the usual structural condition for shafts, gears and heavy springs. | 1,080 | 1,150 | 15 | 37 HRC | — |
Q&T, tempered 540 °C | General-purpose machine-part condition with good strength/toughness balance. | 1,080 | 1,150 | 15 | 36 HRC | 8 % IACS |
Q&T, tempered 425 °C | Balanced high-strength spring/gear condition, typical for leaf and coil springs. | 1,360 | 1,450 | 9 | 44 HRC | 7.5 % IACS |
Q&T, tempered 315 °C | High-hardness spring condition; avoid this range if impact toughness matters (tempered-martensite embrittlement). | 1,570 | 1,730 | 6 | 49 HRC | 7.5 % IACS |
Q&T, tempered 205 °C | Maximum-hardness condition for wear surfaces and small springs; very low ductility and notch sensitivity. | 1,730 | 1,930 | 5.5 | 52 HRC | — |
What is 5150?
5150 (UNS G51500) is a medium-carbon chromium alloy steel in the SAE 51xx family, with roughly 0.50 % carbon and chromium added for hardenability and temper resistance. It suits medium-strength shafts, gears, structural forgings and heavy springs, and is stocked hot-rolled, cold-rolled, cold-drawn, annealed, normalized and quenched-and-tempered with draws from 205 °C to 650 °C. Default values are 460 MPa yield, 800 MPa tensile, 18 % elongation and 229 HB. Carbon equivalent near 0.75 makes it a poor welding grade with no corrosion resistance; 4140 is the usual alternative for deeper hardening and toughness. 5150 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). 5150 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 55% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is 5150 used for?
- Coil springs
- Leaf springs
- Axle and drive shafts
- Gears and gear blanks
- Structural forgings
- Torsion bars
- Agricultural and hand-tool components
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
5150 properties
Typical room-temperature values for 5150-HR; bars are the position among steel grades.
Physical3
5150 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
5150 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 55% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
5150 is rated for continuous service to 300°C (572 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
5150 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 5150 takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
5150's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability fair (35/100).
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. 5150 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 5150
Is 5150 easy to machine?
Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; above 40 HRC use CBN/ceramic or grinding.
Can 5150 be welded?
Poor weldability (CE ≈ 0.75) — preheat 250–350 °C, low-hydrogen consumables and immediate post-weld temper are mandatory.
Can 5150 be formed, bent or molded?
Hot forge 1150–1200 °C, finish above 900 °C, then anneal or normalize; cold forming only for light bends in annealed strip.
Manufacturability
The process limits FabDigit applies to 5150. Every 5150 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better35 / 100 |
|---|---|
| Weldability | Fair25 / 100 |
5150 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 | 0.48 – 0.53 | 0.5 |
| Mn | 0.7 – 0.9 | 0.8 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.7 – 0.9 | 0.8 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 5150?
No natural corrosion resistance — phosphate + oil, black oxide, zinc plating, paint or hard chrome; shot peen springs to boost fatigue life.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 5150 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G51500
How much does 5150 cost?
5150 is a standard-cost steel ($$), cheaper than about 71% 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.
5150 — frequently asked
What is 5150 used for?
5150 is typically used for coil springs, leaf springs, axle and drive shafts, gears and gear blanks, structural forgings and torsion bars. In short: workhorse chrome spring bar.
What is the yield strength of 5150?
5150 has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 55% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 5150 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; above 40 HRC use CBN/ceramic or grinding.
Can 5150 be welded?
Not readily — weldability is rated poor (25/100). Poor weldability (CE ≈ 0.75) — preheat 250–350 °C, low-hydrogen consumables and immediate post-weld temper are mandatory.
What surface finishes work on 5150?
No natural corrosion resistance — phosphate + oil, black oxide, zinc plating, paint or hard chrome; shot peen springs to boost fatigue life.
Can 5150 be formed, bent or molded?
Hot forge 1150–1200 °C, finish above 900 °C, then anneal or normalize; cold forming only for light bends in annealed strip.
What is the maximum service temperature of 5150?
5150 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 5150-HR and 5150-CD?
HR is the default condition — as-rolled bar/plate stock for parts that will be machined and then heat treated. CD: cold-drawn bar giving tight size tolerance, better surface finish and higher as-supplied strength than hot rolled. Yield strength is 460 MPa in HR versus 760 MPa in CD.
How much does 5150 cost?
5150 is a standard-cost steel ($$), cheaper than about 71% 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.
Can FabDigit make parts in 5150?
Yes — 5150 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
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- GB/T 3077 (50Cr) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
- Mysteel / SMM (2025)
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.