Nickel Alloy Chromel Annealed
Temper · default condition
Standard stocked condition for thermocouple wire, extension/compensating cable conductor and MI-cable cores; best emf stability and bendability.
Values for the Annealed condition
Other Chromel tempers and conditions
Chromel is listed in 6 conditions; see the grade overview at Chromel.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefaultThis page soft, fully recrystallized thermocouple wire | Standard stocked condition for thermocouple wire, extension/compensating cable conductor and MI-cable cores; best emf stability and bendability. | 275 | 655 | 35 | 80 HRB | — |
Standard limits of error | Ordinary calibration grade for general industrial K-type thermocouples and extension wire. | 275 | 655 | 35 | 150 HB | 2.4 % IACS |
Stress relieved | Low-temperature stabilizing treatment after coiling or forming to remove cold-work drift and restore calibrated thermoelectric output. | 330 | 700 | 30 | 160 HB | 2.4 % IACS |
Quarter hard | Choose when slightly stiffer wire is needed for automatic winding or probe assembly while retaining good ductility. | 480 | 760 | 20 | 190 HB | 2.4 % IACS |
Half hard | Stiffer wire and strip for self-supporting sensor elements and formed contacts; anneal after forming to restore emf stability. | 690 | 900 | 10 | 21 HRC | 2.3 % IACS |
Hard Drawn | Maximum strength and springiness for resistance/heating windings and fine wire handling; emf output shifts slightly until stress-relieved. | 900 | 1,100 | 3 | 28 HRC | 2.4 % IACS |
What is Chromel Annealed?
Chromel Annealed is Chromel in the Annealed temper — standard stocked condition for thermocouple wire, extension/compensating cable conductor and MI-cable cores; best emf stability and bendability. Chromel Annealed has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 83% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 186 GPa (27 Msi). Chromel Annealed has a density of 8.73 g/cm³ (0.315 lb/in³), heavier than 77% of nickel alloy grades. It melts at 1,400°C (2,552 °F).
Advantages
- Forms and bends easily — 90/100, better than 98% of nickel alloy grades
- High service temperature — 1,100°C (2,012 °F), better than 88% of nickel alloy grades
- Conducts heat well — 19.2 W/m·K (11.1 BTU/hr·ft·°F), better than 86% of nickel alloy grades
- High electrical conductivity — 2.4 % IACS, better than 84% of nickel alloy grades
Limitations
- Low strength — 275 MPa (39.9 ksi), worse than 83% of nickel alloy grades
- Needs corrosion protection — 68/100, worse than 82% of nickel alloy grades
Chromel Annealed properties
Typical room-temperature values for Chromel Annealed; 11 are specific to this condition. Other listed values are Chromel reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
Chromel Annealed has a density of 8.73 g/cm³ (0.315 lb/in³), heavier than 77% of nickel alloy grades. It melts at 1,400°C (2,552 °F).
Mechanical13
Chromel Annealed has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 83% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 186 GPa (27 Msi).
Thermal6
Chromel Annealed is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 19.2 W/m·K (11.1 BTU/hr·ft·°F), better than 86% of nickel alloy grades. Thermal expansion is 13.1 µm/m·K (7.28 µin/in·°F).
Electrical3
Chromel Annealed conducts electricity at 2.4 % IACS, better than 84% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), worse than 82% of nickel alloy grades.
Sustainability4
Producing a kilogram of Chromel Annealed takes about 175 MJ of energy and emits 12.5 kg of CO₂ — more than 65% of nickel alloy grades. Typical recycled content is 25%.
Manufacturability8
Chromel Annealed's machinability is poor (28/100, better than 82% of nickel alloy grades); weldability very good (75/100); formability excellent (90/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Chromel Annealed
Is Chromel easy to machine?
Gummy austenitic Ni-Cr solid solution — use sharp positive-rake carbide, rigid setups, low speed with heavy positive feed and flood coolant to avoid work hardening; rarely machined since the alloy is sold as wire.
Can Chromel be welded?
Readily joined by capacitor-discharge, resistance or TIG welding of the thermocouple junction; keep the hot junction free of dissimilar filler and avoid sulphur-bearing fluxes.
Can Chromel be formed, bent or molded?
Excellent cold drawability and bendability in the annealed temper (down to fine gauges); interanneal cold-worked wire and stress-relieve after coiling to recover emf accuracy.
What surface finishes work on Chromel?
Not anodizable; pre-oxidation in clean air forms a protective Cr₂O₃ film, and wire can be electroplated or glass/ceramic-fibre or MgO-insulated for service.
Chromel 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 |
|---|---|---|
| Crgives the positive Seebeck slope and oxidation resistance | 9 – 10.5 | 10 |
| Fe | ≤ 0.5 | 0.2 |
| Sideoxidizer, small emf effect | ≤ 0.4 | 0.2 |
| Mn | ≤ 0.5 | 0.2 |
| C | ≤ 0.15 | 0.05 |
| Skept low to avoid sulphur embrittlement | ≤ 0.02 | — |
| Nibalance, nominally ~90 % | balance | — |
Chromel Annealed — frequently asked
What is Chromel Annealed used for?
Chromel Annealed is typically used for type K thermocouples, temperature sensor wire, mineral-insulated thermocouple cable conductors, furnace and kiln thermocouple probes, type K extension and compensating cable and surface and immersion sensor assemblies. In short: type K positive leg; stable emf to 1100 °C; excellent fine-wire drawability.
What is the yield strength of Chromel Annealed?
Chromel Annealed has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 83% of nickel alloy grades. Strength varies by condition: see the 6 listed tempers.
Is Chromel Annealed easy to machine?
Not especially — machinability is rated poor (28/100, better than 82% of nickel alloy grades). Gummy austenitic Ni-Cr solid solution — use sharp positive-rake carbide, rigid setups, low speed with heavy positive feed and flood coolant to avoid work hardening; rarely machined since the alloy is sold as wire.
Can Chromel Annealed be welded?
Yes — weldability is rated very good (75/100). Readily joined by capacitor-discharge, resistance or TIG welding of the thermocouple junction; keep the hot junction free of dissimilar filler and avoid sulphur-bearing fluxes.
What surface finishes work on Chromel Annealed?
Not anodizable; pre-oxidation in clean air forms a protective Cr₂O₃ film, and wire can be electroplated or glass/ceramic-fibre or MgO-insulated for service.
Can Chromel Annealed be formed, bent or molded?
Excellent cold drawability and bendability in the annealed temper (down to fine gauges); interanneal cold-worked wire and stress-relieve after coiling to recover emf accuracy.
What is the maximum service temperature of Chromel Annealed?
Chromel Annealed is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Chromel Annealed and Chromel-HD?
Annealed is the default condition — standard stocked condition for thermocouple wire, extension/compensating cable conductor and MI-cable cores; best emf stability and bendability. HD: maximum strength and springiness for resistance/heating windings and fine wire handling; emf output shifts slightly until stress-relieved. Yield strength is 275 MPa in Annealed versus 900 MPa in HD.
Sources
- ASTM E230/E230M — Standard Specification and Temperature-EMF Tables for Standardized Thermocouples — ASTM International (2023)
- IEC 60584-1 Thermocouples — EMF specifications and tolerances — IEC (2013)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- Thermocouple alloy physical property tables (Chromel/Alumel type K legs) — Hoskins / Omega Engineering (2022)
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.