Steel 4161
AISI/SAE 4161 · UNS G41610
4161 is the highest-carbon chromium-molybdenum grade in the SAE-AISI 41xx family (UNS G41610), used where spring-level strength and deep hardenability are required.
Reference datasheet — 4161 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
4161 tempers and conditions
4161 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 |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for cold heading, deep drawing or heavy cold forming of this high-carbon grade. | 390 | 700 | 22 | 11 HRC | 8.1 % IACS |
ADefault Solution annealed | Softest supply condition for machining, cold forming and subsequent hardening by the user. | 415 | 760 | 18 | 217 HB | — |
Hot rolled | Lowest-cost mill condition for spring blanks and forging stock that will be heat treated afterwards. | 550 | 900 | 14 | 26 HRC | 7.8 % IACS |
Normalized | Uniform fine pearlitic structure for forgings prior to machining or hardening; higher strength than annealed. | 700 | 1,080 | 12 | 34 HRC | — |
Cold drawn | Bright, close-tolerance bar with raised yield strength for shafts machined without further heat treatment. | 760 | 900 | 10 | 26 HRC | 7.8 % IACS |
Q&T 650 °C | Softest Q&T condition — maximum ductility and machinability while retaining tempered-martensite structure. | 895 | 965 | 18 | 30 HRC | — |
Q&T 540 °C | Tough quenched-and-tempered condition for shock-loaded shafts and machined high-strength parts. | 1,145 | 1,240 | 14 | 38 HRC | — |
Q&T 425 °C | Typical leaf/coil spring and heavy shaft condition — best balance of fatigue strength and toughness. | 1,415 | 1,550 | 11 | 45 HRC | — |
Q&T 315 °C | Very high strength for heavily loaded springs and torsion bars where some ductility is still needed. | 1,620 | 1,855 | 8 | 53 HRC | — |
Q&T 205 °C | Maximum hardness and strength for wear-critical tooling; very low toughness, avoid notches and impact. | 1,725 | 2,035 | 6 | 57 HRC | — |
What is 4161?
4161 is the highest-carbon chromium-molybdenum grade in the SAE-AISI 41xx family (UNS G41610), used where spring-level strength and deep hardenability are required. It is supplied annealed, spheroidize-annealed, normalized, hot-rolled, cold-drawn and in tempered conditions from QT205 to QT650 as bar, flats and spring stock. Default-condition values are 415 MPa yield, 760 MPa tensile, 18 % elongation and 217 HB (96 HRB), with service to about 400 °C, machinability 48 and formability 35. Weldability is poor (CE ≈ 0.95) and it has no corrosion resistance; 5160 is the usual alternative for heavy springs. 4161 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). 4161 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is 4161 used for?
- heavy springs
- high-strength shafts
- gears
Limitations
- Difficult to weld — 20/100, worse than 84% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
4161 properties
Typical room-temperature values for 4161-A; bars are the position among steel grades.
Physical3
4161 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical16
4161 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4161 is rated for continuous service to 400°C (752 °F). It conducts heat at 42.7 W/m·K (24.7 BTU/hr·ft·°F), better than 50% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
4161 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 4161 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
4161's machinability is fair (48/100, worse than 57% of steel grades); weldability poor (20/100); 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. 4161 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 4161
Is 4161 easy to machine?
Machine in the annealed/spheroidized state (~55 % of 1212); above 40 HRC use carbide or CBN with rigid setups, or finish by grinding.
Can 4161 be welded?
Poor weldability — CE ≈ 0.95; if unavoidable, preheat 300–350 °C, use low-hydrogen consumables and temper immediately after welding.
Can 4161 be formed, bent or molded?
Cold form only in spheroidize-annealed condition with generous radii; hot forge 1100–1200 °C and always normalize/anneal afterwards; oil quench from 830–860 °C and temper at once to avoid quench cracking.
4161 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 |
|---|---|---|
| Chighest carbon of the 41xx family | 0.56 – 0.64 | 0.6 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.7 – 0.9 | 0.8 |
| Mo | 0.25 – 0.35 | 0.3 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 4161?
No anodizing; use black oxide, manganese phosphate + oil, zinc or Cr plating (bake 190 °C ≥4 h after plating to avoid hydrogen embrittlement); shot peening greatly boosts spring 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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 4161 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G41610
How much does 4161 cost?
4161 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.
4161 — frequently asked
What is 4161 used for?
4161 is typically used for heavy springs, high-strength shafts and gears. In short: highest-carbon 41xx grade; spring-strength Cr-Mo steel; very limited weldability.
What is the yield strength of 4161?
4161 has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 4161 easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machine in the annealed/spheroidized state (~55 % of 1212); above 40 HRC use carbide or CBN with rigid setups, or finish by grinding.
Can 4161 be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — CE ≈ 0.95; if unavoidable, preheat 300–350 °C, use low-hydrogen consumables and temper immediately after welding.
What surface finishes work on 4161?
No anodizing; use black oxide, manganese phosphate + oil, zinc or Cr plating (bake 190 °C ≥4 h after plating to avoid hydrogen embrittlement); shot peening greatly boosts spring fatigue life.
Can 4161 be formed, bent or molded?
Cold form only in spheroidize-annealed condition with generous radii; hot forge 1100–1200 °C and always normalize/anneal afterwards; oil quench from 830–860 °C and temper at once to avoid quench cracking.
What is the maximum service temperature of 4161?
4161 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 4161-A and 4161-QT205?
A is the default condition — softest supply condition for machining, cold forming and subsequent hardening by the user. QT205: maximum hardness and strength for wear-critical tooling; very low toughness, avoid notches and impact. Yield strength is 415 MPa in A versus 1,725 MPa in QT205.
How much does 4161 cost?
4161 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)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating — ASM International (1991)
- 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.