Steel L1 QT-62
Hardness band
AISI/SAE L1 · UNS T61201
QT-62 = oil hardened + tempered 150–175 °C
Maximum wear resistance for gauges, taps, reamers and rolls where impact is low.
Values for the QT-62 condition
Other L1 tempers and conditions
L1 is listed in 11 conditions; see the grade overview at L1.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard stock condition for bar and flats — soft enough to machine before hardening. | 415 | 725 | 22 | 195 HB | 41 W/m·K |
Stress relieved | Intermediate treatment between rough and finish machining to minimize hardening distortion. | 430 | 740 | 20 | 200 HB | 8.5 % IACS |
Hot rolled | Mill hot-rolled black bar; normally re-annealed before machining. | 490 | 850 | 14 | 22 HRC | 8.5 % IACS |
Normalized | Grain-refining step before hardening of heavily forged or re-worked stock. | 520 | 900 | 12 | 25 HRC | 8.5 % IACS |
Cold drawn, annealed | Close-tolerance drawn or ground bar for shafts, mandrels and pins machined near-net. | 570 | 790 | 14 | 18 HRC | 8.5 % IACS |
Oil hardened + tempered ≈480–510 °C | Maximum-toughness hardened level for machine parts, collars and springs-like sections. | 1,270 | 1,450 | 10 | 45 HRC | — |
Oil hardened + tempered ≈400 °C | Use when shock loading dominates and moderate wear resistance is sufficient. | 1,480 | 1,700 | 7 | 51 HRC | — |
Oil hardened + tempered ≈260–315 °C | Tougher hardened level for shafts, cams, arbors and lightly impacted tooling. | 1,650 | 1,900 | 4 | 56 HRC | — |
Oil hardened + tempered ≈205 °C | General-purpose hardened condition balancing wear resistance and chipping risk. | 1,800 | 2,100 | 2 | 60 HRC | — |
As-quenched | Intermediate condition only — must be tempered immediately to avoid cracking. | 1,900 | 2,250 | 0.5 | 64 HRC | 7 % IACS |
QT-62This page Oil hardened + tempered 150–175 °C | Maximum wear resistance for gauges, taps, reamers and rolls where impact is low. | 1,950 | 2,300 | 1 | 63 HRC | 34 W/m·K |
What is L1 QT-62?
L1 QT-62 is L1 heat treated to QT-62 — maximum wear resistance for gauges, taps, reamers and rolls where impact is low. L1 QT-62 has a yield strength of 1,950 MPa (283 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 1% and the elastic modulus is 205 GPa (29.7 Msi). L1 QT-62 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). ANN is the default condition FabDigit quotes; QT-62 is available on request or by drawing note.
Advantages
- High strength — 1,950 MPa (283 ksi), better than 100% of steel grades
- Polishes to a fine finish — 80/100, better than 97% of steel grades
Limitations
- Limited service temperature — 140°C (284 °F), worse than 100% of steel grades
- Difficult to machine — 5/100, worse than 100% of steel grades
- Limited ductility — 1%, worse than 99% of steel grades
- Difficult to weld — 12/100, worse than 96% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
L1 QT-62 properties
Typical room-temperature values for L1 QT-62; 13 are specific to this condition. Other listed values are L1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
L1 QT-62 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
L1 QT-62 has a yield strength of 1,950 MPa (283 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 1% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
L1 QT-62 is rated for continuous service to 140°C (284 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
L1 QT-62 conducts electricity at 8.5 % IACS, better than 63% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of L1 QT-62 takes about 33 MJ of energy and emits 2.4 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 30%.
Manufacturability8
L1 QT-62's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (12/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with L1 QT-62
Is L1 easy to machine?
Machine in the spheroidize-annealed state (~65 % of AISI 1212); after hardening only grinding, EDM or CBN turning is practical.
Can L1 be welded?
Poor weldability — high carbon promotes cracking; if repair is unavoidable, preheat 300–350 °C, use matching or low-hydrogen filler and temper immediately.
Can L1 be formed, bent or molded?
Hot forge 1050→850 °C with slow cooling and a full anneal; cold forming limited to mild bending of annealed thin sections.
What surface finishes work on L1?
Takes a fine polish when hardened; protect with oil, black oxide, phosphating or hard chrome — the alloy has essentially no corrosion resistance.
L1 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 |
|---|---|---|
| Chigh carbon gives 62-64 HRC after oil quench | 0.95 – 1.1 | 1 |
| Mn | 0.1 – 0.4 | 0.25 |
| Si | 0.1 – 0.4 | 0.25 |
| Crcarbide former, adds hardenability and wear resistance | 1 – 1.5 | 1.25 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
L1 QT-62 — frequently asked
What is L1 QT-62 used for?
L1 QT-62 is typically used for arbors, cams, collets and rolls. In short: tough oil-hardening L-series steel; good annealed machinability (55); 41 W/m·K thermal conductivity.
What is the yield strength of L1 QT-62?
L1 QT-62 has a typical yield strength of 1,950 MPa (283 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is L1 QT-62 easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% of steel grades). Machine in the spheroidize-annealed state (~65 % of AISI 1212); after hardening only grinding, EDM or CBN turning is practical.
Can L1 QT-62 be welded?
Not readily — weldability is rated not recommended (12/100). Poor weldability — high carbon promotes cracking; if repair is unavoidable, preheat 300–350 °C, use matching or low-hydrogen filler and temper immediately.
What surface finishes work on L1 QT-62?
Takes a fine polish when hardened; protect with oil, black oxide, phosphating or hard chrome — the alloy has essentially no corrosion resistance.
Can L1 QT-62 be formed, bent or molded?
Hot forge 1050→850 °C with slow cooling and a full anneal; cold forming limited to mild bending of annealed thin sections.
What is the maximum service temperature of L1 QT-62?
L1 QT-62 is rated for continuous use to about 140°C (284 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between L1-ANN and L1 QT-62?
ANN is the default condition — standard stock condition for bar and flats — soft enough to machine before hardening. QT-62: maximum wear resistance for gauges, taps, reamers and rolls where impact is low. Yield strength is 415 MPa in ANN versus 1,950 MPa in QT-62.
Sources
- ASTM A681 — Standard Specification for Tool Steels, Alloy — ASTM 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 (machinability ratings of tool steels) — ASM International (1989)
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.