Steel 5135
AISI/SAE 5135 · UNS G51350
5135 (UNS G51350, also known as 35Cr) is a chromium alloy steel in the SAE-AISI 51xx family with higher carbon than 5130, giving good hardenability and wear resistance for heavier-duty structural and drivetrain parts.
Reference datasheet — 5135 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 A condition
5135 tempers and conditions
5135 is supplied in 10 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Softest, most machinable and most formable condition; standard stock for parts that will be Q&T later. | 300 | 570 | 28 | 165 HB | — |
Hot rolled | Cheapest mill condition for parts that will be fully heat treated after machining. | 420 | 700 | 22 | 200 HB | — |
Normalized | Uniform fine-grain structure with moderate strength; good baseline for forgings and for parts not requiring Q&T. | 440 | 740 | 24 | 217 HB | — |
Cold drawn | Close tolerance, bright-finish bar with raised yield strength for shafts and studs used without further heat treatment. | 620 | 720 | 13 | 212 HB | — |
Q&T 650 °C | Softest tempered condition; choose when toughness and machinability outrank strength. | 720 | 850 | 22 | 24 HRC | — |
Q&T 540 °C | Choose oil quenched and tempered at 540 °C (≈30 HRC) for shafts, axles and connecting rods needing the classic strength/toughness balance of 830 MPa yield with 17% elongation. | 830 | 1,010 | 17 | 31 HRC | — |
Induction hardened | Selective surface hardening for journals, spline and gear teeth needing wear resistance over a tough core. | 830 | 1,010 | 15 | 55 HRC | 7.5 % IACS |
Q&T 425 °C | High-strength condition (≈38-40 HRC) for gears, spline shafts and high-tensile fasteners. | 1,120 | 1,240 | 15 | 39 HRC | — |
Q&T 315 °C | Very high strength for springs and highly stressed wear parts; ductility still low. | 1,360 | 1,500 | 12 | 45 HRC | — |
Q&T 205 °C | Maximum hardness and wear resistance; use only for lightly loaded, non-impact wear parts. | 1,450 | 1,660 | 10 | 49 HRC | — |
What is 5135?
5135 (UNS G51350, also known as 35Cr) is a chromium alloy steel in the SAE-AISI 51xx family with higher carbon than 5130, giving good hardenability and wear resistance for heavier-duty structural and drivetrain parts. It is available hot rolled, annealed, normalized, cold drawn, induction hardened and quenched and tempered from 205 °C to 650 °C, typically as bar and forging stock. Annealed reference values are 300 MPa yield, 570 MPa tensile, 28 % elongation and 165 HB (85 HRB), with machinability 55 and weldability 48. There is no corrosion resistance and welding needs preheat and tempering; 5132 machines more freely at lower strength. 5135 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). 5135 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 86% of steel grades. Elongation at break is 28% and the elastic modulus is 205 GPa (29.7 Msi).
What is 5135 used for?
- gears
- shafts
- connecting rods
- structural forgings
- springs
Advantages
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 86% of steel grades
5135 properties
Typical room-temperature values for 5135-A; bars are the position among steel grades.
Physical3
5135 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).
Mechanical14
5135 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 86% of steel grades. Elongation at break is 28% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
5135 is rated for continuous service to 400°C (752 °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).
Electrical3
5135 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 5135 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability7
5135's machinability is good (55/100, better than 62% of steel grades); weldability fair (48/100); formability fair (50/100).
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. 5135 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 5135
Is 5135 easy to machine?
Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; expect ~60 % of 1212 speed and grind rather than turn above 45 HRC.
Can 5135 be welded?
Weldable with low-hydrogen consumables but needs 200–320 °C preheat, controlled interpass and immediate stress-relief/temper to avoid martensitic HAZ cracking; weld before hardening where possible.
Can 5135 be formed, bent or molded?
Cold form only in the annealed/spheroidized state with generous bend radii; hot forge 1100–1200 °C, finish above 850 °C and slow-cool or normalize afterwards.
5135 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 |
|---|---|---|
| CSAE 5135 / GB 35Cr | 0.33 – 0.38 | 0.35 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.8 | 0.7 |
| CrGB 35Cr: 0.80–1.10 | 0.8 – 1.05 | 0.95 |
| P | ≤ 0.04 | |
| Smax; 0.015–0.035 for resulfurized variants | ≤ 0.04 | |
| Niresidual (GB/T 3077) | ≤ 0.3 | |
| Curesidual | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on 5135?
No anodizing — protect by zinc or hard-chrome plating, phosphate + oil, black oxide or paint; nitriding and induction hardening give excellent 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 5135 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G51350
- Similar grades
- 35Cr
How much does 5135 cost?
5135 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.
5135 — frequently asked
What is 5135 used for?
5135 is typically used for gears, shafts, connecting rods, structural forgings and springs. In short: higher-carbon 51xx workhorse; good hardenability and wear; nitriding-friendly chromium steel.
What is the yield strength of 5135?
5135 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 5135 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; expect ~60 % of 1212 speed and grind rather than turn above 45 HRC.
Can 5135 be welded?
With care — weldability is rated fair (48/100). Weldable with low-hydrogen consumables but needs 200–320 °C preheat, controlled interpass and immediate stress-relief/temper to avoid martensitic HAZ cracking; weld before hardening where possible.
What surface finishes work on 5135?
No anodizing — protect by zinc or hard-chrome plating, phosphate + oil, black oxide or paint; nitriding and induction hardening give excellent wear surfaces.
Can 5135 be formed, bent or molded?
Cold form only in the annealed/spheroidized state with generous bend radii; hot forge 1100–1200 °C, finish above 850 °C and slow-cool or normalize afterwards.
What is the maximum service temperature of 5135?
5135 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 5135-A and 5135-QT205?
A is the default condition — softest, most machinable and most formable condition; standard stock for parts that will be Q&T later. QT205: maximum hardness and wear resistance; use only for lightly loaded, non-impact wear parts. Yield strength is 300 MPa in A versus 1,450 MPa in QT205.
How much does 5135 cost?
5135 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
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- GB/T 3077 (35Cr) — SAC/ (2015)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A — Steel Heat Treating Fundamentals and Processes — ASM International (2013)
- ASM Handbook Vol. 16 — Machining — ASM International (1989)
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.