Steel L3
AISI/SAE L3 · UNS T61203
L3 is a chromium–vanadium low-alloy tool steel (UNS T61203) with a higher carbide content than L2, giving improved wear resistance and dimensional stability through heat treatment.
Reference datasheet — L3 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 ANN condition
L3 tempers and conditions
L3 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard as-supplied bar/flat condition for machining and forming before hardening. | 430 | 730 | 25 | 197 HB | — |
Cold drawn / ground annealed bar | Precision-ground annealed bar and drill rod for direct machining to size before hardening. | 550 | 780 | 15 | 17 HRC | 8 % IACS |
Hardened & tempered 315–370 °C | Tougher setting for shock-loaded punches, chisels and shafts where some wear resistance is traded for impact life. | 1,650 | 1,900 | 4 | 55 HRC | — |
Hardened & tempered 205–260 °C | Balanced wear/toughness condition for punches, forming rolls and arbors. | 1,850 | 2,100 | 2 | 59 HRC | — |
Hardened & tempered 150–175 °C | Maximum hardness/wear condition for gauges, ball races and cutting-edge tools with light shock. | 2,050 | 2,350 | 1 | 63 HRC | 34 W/m·K |
What is L3?
L3 is a chromium–vanadium low-alloy tool steel (UNS T61203) with a higher carbide content than L2, giving improved wear resistance and dimensional stability through heat treatment. Annealed and cold-drawn-annealed bar measures 197 HB with 730 MPa tensile, 430 MPa yield and 25 % elongation; quenched-and-tempered conditions cover approximately 55, 59 and 62 HRC for gauges, mandrels and precision tooling. Weldability is rated 15, maximum service temperature is 200 °C and the steel has no corrosion resistance. L2 is the tougher, lower-carbide alternative. L3 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). L3 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Elongation at break is 25% and the elastic modulus is 207 GPa (30 Msi).
What is L3 used for?
- gauges
- precision tools
- mandrels
- wear-resistant machine parts
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
L3 properties
Typical room-temperature values for L3-ANN; bars are the position among steel grades.
Physical3
L3 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).
Mechanical15
L3 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Elongation at break is 25% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
L3 is rated for continuous service to 200°C (392 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
L3 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 L3 takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
L3's machinability is good (55/100, better than 62% of steel grades); weldability poor (15/100); 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. L3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with L3
Is L3 easy to machine?
Machine only in the spheroidize-annealed condition (~200 HB) with sharp carbide or cobalt HSS at moderate speeds; after hardening above 58 HRC only grinding, EDM or CBN turning is practical.
Can L3 be welded?
Essentially not weldable in service condition — high carbon causes quench cracking; repair only with preheat 300–350 °C, matching/tool-steel electrode and immediate stress relief or re-temper.
Can L3 be formed, bent or molded?
Hot work 900–1050 °C with slow cooling and full spheroidize anneal (760–790 °C, slow cool to ~590 °C); cold forming is limited to mild bending of annealed stock.
L3 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 | 0.95 – 1.1 | 1 |
| Mn | 0.25 – 0.8 | 0.45 |
| Si | 0.1 – 0.5 | 0.25 |
| Cr | 1.3 – 1.7 | 1.5 |
| Vgrain refinement + hard MC carbides | 0.1 – 0.3 | 0.2 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on L3?
Hardened parts polish to a fine mirror finish thanks to the fine carbide dispersion; protect with oil, black oxide, phosphate or thin hard chrome since the steel has no corrosion resistance.
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 L3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T61203
How much does L3 cost?
L3 is a premium-cost steel ($$$), cheaper than about 51% 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.
L3 — frequently asked
What is L3 used for?
L3 is typically used for gauges, precision tools, mandrels and wear-resistant machine parts. In short: higher wear than L2; dimensionally stable gauge steel; polishes to mirror finish.
What is the yield strength of L3?
L3 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is L3 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine only in the spheroidize-annealed condition (~200 HB) with sharp carbide or cobalt HSS at moderate speeds; after hardening above 58 HRC only grinding, EDM or CBN turning is practical.
Can L3 be welded?
Not readily — weldability is rated poor (15/100). Essentially not weldable in service condition — high carbon causes quench cracking; repair only with preheat 300–350 °C, matching/tool-steel electrode and immediate stress relief or re-temper.
What surface finishes work on L3?
Hardened parts polish to a fine mirror finish thanks to the fine carbide dispersion; protect with oil, black oxide, phosphate or thin hard chrome since the steel has no corrosion resistance.
Can L3 be formed, bent or molded?
Hot work 900–1050 °C with slow cooling and full spheroidize anneal (760–790 °C, slow cool to ~590 °C); cold forming is limited to mild bending of annealed stock.
What is the maximum service temperature of L3?
L3 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.
What is the difference between L3-ANN and L3 QT-62?
ANN is the default condition — standard as-supplied bar/flat condition for machining and forming before hardening. QT-62: maximum hardness/wear condition for gauges, ball races and cutting-edge tools with light shock. Yield strength is 430 MPa in ANN versus 2,050 MPa in QT-62.
How much does L3 cost?
L3 is a premium-cost steel ($$$), cheaper than about 51% 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
- ASTM A681 — Standard Specification for Tool Steels, Alloy — ASTM International (2015)
- SAE J437/J438 — Tool and Die Steels — SAE International (2015)
- ASM Handbook Vol. 1: Properties and Selection: Irons, Steels and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- ASM Handbook Vol. 16: Machining — ASM International (1989)
- UNS T61203 alloy record — SAE/ASTM Unified Numbering System (2019)
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.