Copper Alloy TU1
GB TU1 · ASTM B170 · EN CW008A, Cu-OFE · JIS C1011
TU1 is a high-purity oxygen-free copper of minimum 99.97 % Cu, matching C10100 / Cu-OFE / CW008A, supplied for electronic and vacuum service.
Reference datasheet — TU1 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 OS050 condition
TU1 tempers and conditions
TU1 is supplied in 13 conditions, soft to hard. OS050 is the default FabDigit quotes; the values on this page are for it.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled and annealed | Soft plate/forging stock condition for machined UHV chambers, waveguides and heavy conductors. | 62 | 220 | 48 | 42 HB | 101 % IACS |
OS050Default Annealed to 0.050 mm grain size | Standard stocked soft condition for deep drawing, forming, vacuum-brazed and UHV parts. | 69 | 221 | 45 | 45 HB | 101 % IACS |
Annealed to 0.025 mm grain size | Fine-grain annealed strip for thin-gauge stamping where orange-peel must be avoided. | 83 | 234 | 42 | 50 HB | 101 % IACS |
As hot rolled | Mill hot-rolled bar/plate for parts that will be machined and later annealed or brazed. | 90 | 235 | 40 | 50 HB | 101 % IACS |
1/8 hard | Slight cold work for improved flatness and handling stiffness while keeping good formability. | 160 | 234 | 30 | 55 HB | 101 % IACS |
Light drawn | Lightly drawn rod/tube giving straightness and modest strength while retaining bendability. | 200 | 262 | 25 | 65 HB | 101 % IACS |
Quarter hard | Best compromise of stiffness and bendability for stamped busbars, clips and shields. | 205 | 262 | 25 | 60 HB | 101 % IACS |
Half hard | Most common semi-rigid strip/bar temper for busbar, terminals and gaskets needing some springback. | 250 | 290 | 14 | 75 HB | 101 % IACS |
Full hard | Rigid strip/sheet for flat springs, contacts and stiff conductors where only mild forming is needed. | 310 | 345 | 6 | 90 HB | 100 % IACS |
Extra hard | High-strength strip for flat springs and contact blades with minimal forming. | 345 | 379 | 4 | 95 HB | 100 % IACS |
Hard drawn | Fully hard-drawn rod/wire for overhead and high-strength conductors, commutator bars and machined parts. | 345 | 379 | 10 | 100 HB | 100 % IACS |
Spring hard | Spring-tempered strip for high-conductivity contact springs and EMI fingerstock. | 365 | 393 | 4 | 100 HB | 100 % IACS |
Extra spring hard | Maximum cold-rolled strength of the strip series; only flat or very gentle forms. | 372 | 400 | 4 | 105 HB | 100 % IACS |
What is TU1?
TU1 is a high-purity oxygen-free copper of minimum 99.97 % Cu, matching C10100 / Cu-OFE / CW008A, supplied for electronic and vacuum service. It combines 101 % IACS and 391 W/m·K with 69 MPa yield, 221 MPa tensile and 45 % elongation soft, is rated to about 250 °C, and comes as rod, plate, strip and tube across annealed OS/O tempers through H80. The absence of oxygen removes the hydrogen-embrittlement problem of tough-pitch copper, giving a weldability score of 70, but the alloy is expensive, gummy to machine (score 28) and softens rapidly with heat. Where the vacuum and hydrogen-brazing requirement does not apply, TU2 or T2 costs less. TU1 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F). TU1 has a yield strength of 69 MPa (10 ksi) and a tensile strength of 221 MPa (32.1 ksi) — weaker than 96% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 115 GPa (16.7 Msi).
What is TU1 used for?
- vacuum electronics
- high-conductivity conductors
- waveguides
- welding electrode tips
Advantages
- Conducts heat well — 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades
- High electrical conductivity — 101 % IACS, better than 98% of copper alloy grades
- Forms and bends easily — 95/100, better than 94% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
Limitations
- Low strength — 69 MPa (10 ksi), worse than 96% of copper alloy grades
TU1 properties
Typical room-temperature values for TU1-OS050; bars are the position among copper alloy grades.
Physical3
TU1 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F).
Mechanical11
TU1 has a yield strength of 69 MPa (10 ksi) and a tensile strength of 221 MPa (32.1 ksi) — weaker than 96% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
TU1 is rated for continuous service to 250°C (482 °F). It conducts heat at 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
TU1 conducts electricity at 101 % IACS, better than 98% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of TU1 takes about 60 MJ of energy and emits 4 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 15%.
Manufacturability8
TU1's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability very good (70/100); formability excellent (95/100).
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 copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. TU1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with TU1
Is TU1 easy to machine?
Gummy and stringy — use sharp, high-positive-rake carbide or PCD tools, high speed with low feed, generous flood coolant; expect ~20% of AISI 1212 productivity, avoid work-hardened rubbing.
Can TU1 be welded?
Excellent for TIG/EB/laser and vacuum brazing because there is no oxygen to cause hydrogen embrittlement; preheat 200–500 °C on thick sections due to the very high thermal conductivity.
Can TU1 be formed, bent or molded?
Outstanding cold formability in OS050/O25 (deep draw, spin, coin); interanneal at 400–600 °C after roughly 50–70% reduction, hard tempers must be bent with generous radii along the grain.
TU1 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 |
|---|---|---|
| O≤20 ppm for TU1; ≤5 ppm for C10100 (Cu-OFE) | ≤ 0 | 5×10⁻⁴ |
| P | ≤ 0 | |
| Bi | ≤ 0 | |
| Sb | ≤ 0 | |
| As | ≤ 0 | |
| Fe | ≤ 0 | |
| Ni | ≤ 0 | |
| Pb | ≤ 0 | |
| Sn | ≤ 0 | |
| Zn | ≤ 0 | |
| S | ≤ 0 | |
| CuCu+Ag per GB/T 5231 TU1; C10100 requires 99.99% min | ≥ 99.97 (balance) |
What surface finishes work on TU1?
Not anodisable; mechanically polishes to a mirror and is commonly electroplated with Ni/Ag/Au or chemically cleaned/passivated (citric or dilute acid) for UHV service to control tarnish.
Surface treatments FabDigit runs on copper alloy 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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy TU1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does TU1 cost?
TU1 is a high-cost copper alloy ($$$$), pricier than about 78% 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.
TU1 — frequently asked
What is TU1 used for?
TU1 is typically used for vacuum electronics, high-conductivity conductors, waveguides and welding electrode tips. In short: highest-purity oxygen-free copper; no hydrogen embrittlement; vacuum and UHV grade.
What is the yield strength of TU1?
TU1 has a typical yield strength of 69 MPa (10 ksi) and a tensile strength of 221 MPa (32.1 ksi) — weaker than 96% of copper alloy grades. Strength varies by condition: see the 13 listed tempers.
Is TU1 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Gummy and stringy — use sharp, high-positive-rake carbide or PCD tools, high speed with low feed, generous flood coolant; expect ~20% of AISI 1212 productivity, avoid work-hardened rubbing.
Can TU1 be welded?
Yes — weldability is rated very good (70/100). Excellent for TIG/EB/laser and vacuum brazing because there is no oxygen to cause hydrogen embrittlement; preheat 200–500 °C on thick sections due to the very high thermal conductivity.
What surface finishes work on TU1?
Not anodisable; mechanically polishes to a mirror and is commonly electroplated with Ni/Ag/Au or chemically cleaned/passivated (citric or dilute acid) for UHV service to control tarnish.
Can TU1 be formed, bent or molded?
Outstanding cold formability in OS050/O25 (deep draw, spin, coin); interanneal at 400–600 °C after roughly 50–70% reduction, hard tempers must be bent with generous radii along the grain.
What is the maximum service temperature of TU1?
TU1 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between TU1-OS050 and TU1-H10?
OS050 is the default condition — standard stocked soft condition for deep drawing, forming, vacuum-brazed and UHV parts. H10: maximum cold-rolled strength of the strip series; only flat or very gentle forms. Yield strength is 69 MPa in OS050 versus 372 MPa in H10.
How much does TU1 cost?
TU1 is a high-cost copper alloy ($$$$), pricier than about 78% 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 B170 Oxygen-Free Electrolytic Copper Refinery Shapes — ASTM (2019)
- ASTM B152/B152M Copper Sheet, Strip, Plate and Rolled Bar — ASTM (2019)
- CDA Alloy C10100 property datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- EN 13601 / CW008A Cu-OFE — CEN (2013)
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.