Copper Alloy C18200 · precip hard
Copper Alloy C18200-TH04
Properties of the TH04 condition, compared with the other C18200 tempers.
Highest strength/hardness combination for resistance-welding electrodes, shanks and heavy-duty conductors.
What is C18200-TH04?
C18200-TH04 is C18200 in the TH04 condition — highest strength/hardness combination for resistance-welding electrodes, shanks and heavy-duty conductors. C18200-TH04 has a yield strength of 448 MPa (65 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 117 GPa (17 Msi). C18200-TH04 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 71% of copper alloy grades. It melts at 1,070°C (1,958 °F). H is the default condition FabDigit quotes; TH04 is available on request or by drawing note.
Advantages
- High service temperature — 400°C (752 °F), better than 97% of copper alloy grades
- High strength — 448 MPa (65 ksi), better than 85% of copper alloy grades
- High electrical conductivity — 81 % IACS, better than 83% of copper alloy grades
- Conducts heat well — 320 W/m·K (184.9 BTU/hr·ft·°F), better than 82% of copper alloy grades
C18200-TH04 properties
Typical room-temperature values for C18200-TH04 — 11 properties are specific to this condition; the rest are grade-level values shared by every C18200 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C18200-TH04 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 71% of copper alloy grades. It melts at 1,070°C (1,958 °F).
Mechanical12
C18200-TH04 has a yield strength of 448 MPa (65 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C18200-TH04 is rated for continuous service to 400°C (752 °F). It conducts heat at 320 W/m·K (184.9 BTU/hr·ft·°F), better than 82% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C18200-TH04 conducts electricity at 81 % IACS, better than 83% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C18200-TH04 takes about 57 MJ of energy and emits 3.5 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 30%.
Manufacturability7
C18200-TH04's machinability is fair (42/100, better than 60% of copper alloy grades); weldability poor (30/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C18200 tempers and conditions
C18200 is also supplied in 7 other conditions. The full side-by-side table is on the C18200 overview.
- HDefaultStandard stocked condition for electrode bar and rod: ~75–80 HRB with ≥80% IACS.430 MPa yield · 140 HB
- TH04Highest strength/hardness combination for resistance-welding electrodes, shanks and heavy-duty conductors.448 MPa yield · 145 HB
- TF00Best choice for large sections, forgings and mould inserts where uniform properties and high conductivity matter more than peak strength.372 MPa yield · 120 HB
- TD04Cold-worked strength without the aging step; choose when conductivity is secondary and a later age-hardening cycle will follow.360 MPa yield · 68 HRB
- TB00Pick when heavy cold forming, deep drawing or machining of complex shapes is needed before a final aging cycle.96 MPa yield · 55 HB
Working with C18200-TH04
Is C18200 easy to machine?
Machine in the aged (TH/TF) condition with sharp positive-rake carbide, high speed and generous coolant; gummy and prone to built-up edge when solution treated.
Can C18200 be welded?
Fusion welding is poor — Cr oxide films and hot cracking; prefer brazing, silver soldering or mechanical/threaded joints, and re-age locally softened zones.
Can C18200 be formed, bent or molded?
Form, bend or upset in TB00 (soft) condition then age 450–500 °C for 2–4 h; cold formability drops sharply once aged.
What surface finishes work on C18200?
Not anodizable; use bright turning/polishing, chemical bright dip, or nickel/silver/tin plating for contact surfaces and tarnish resistance.
C18200 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 |
|---|---|---|
| Crprimary precipitation-hardening addition | 0.6 – 1.2 | 0.9 |
| Feimpurity limit | ≤ 0.1 | 0.03 |
| Siimpurity limit | ≤ 0.1 | 0.02 |
| Pbimpurity limit | ≤ 0.05 | 0.01 |
| CuCu + named elements ≥ 99.5 % (Ag countable as Cu) | ≥ 98.6 (balance) | — |
C18200-TH04 — frequently asked
What is C18200-TH04 used for?
C18200-TH04 is typically used for resistance spot-welding electrodes (RWMA Class 2), electrode holders and shanks, switch and breaker contact arms, continuous-casting mould components, injection mould inserts and high-current bus conductors. In short: high-temp conductivity.
What is the yield strength of C18200-TH04?
C18200-TH04 has a typical yield strength of 448 MPa (65 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 85% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C18200-TH04 easy to machine?
Not especially — machinability is rated fair (42/100, better than 60% of copper alloy grades). Machine in the aged (TH/TF) condition with sharp positive-rake carbide, high speed and generous coolant; gummy and prone to built-up edge when solution treated.
Can C18200-TH04 be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is poor — Cr oxide films and hot cracking; prefer brazing, silver soldering or mechanical/threaded joints, and re-age locally softened zones.
What surface finishes work on C18200-TH04?
Not anodizable; use bright turning/polishing, chemical bright dip, or nickel/silver/tin plating for contact surfaces and tarnish resistance.
Can C18200-TH04 be formed, bent or molded?
Form, bend or upset in TB00 (soft) condition then age 450–500 °C for 2–4 h; cold formability drops sharply once aged.
What is the maximum service temperature of C18200-TH04?
C18200-TH04 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 C18200-H and C18200-TB00?
H is the default condition — standard stocked condition for electrode bar and rod: ~75–80 HRB with ≥80% IACS. TB00: pick when heavy cold forming, deep drawing or machining of complex shapes is needed before a final aging cycle. Yield strength is 430 MPa in H versus 96 MPa in TB00.
Can FabDigit make parts in C18200-TH04?
Yes — C18200-TH04 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B224 — Standard Classification of Coppers — ASTM International (2021)
- ASTM B601 — Temper Designations for Copper and Copper Alloys — ASTM International (2019)
- RWMA Bulletin 16 — Resistance Welding Electrode Classification (Class 2) — AWS/RWMA (2017)
- UNS C18200 alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol.2 — Properties of Nonferrous Alloys — ASM International (1990)
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.