Copper Alloy QCr0.5
GB QCr0.5
QCr0.5 is a chromium copper equivalent to C18200, a precipitation-hardening high-conductivity copper supplied as bar, forgings and strip in M, TB00, TD04, TF00 and TH tempers.
Reference datasheet — QCr0.5 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 TF00 condition
QCr0.5 tempers and conditions
QCr0.5 is supplied in 8 conditions, soft to hard. TF00 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Supersaturated, soft and ductile — pick when the part must be formed or machined before precipitation ageing. | 90 | 235 | 42 | 50 HB | 42 % IACS |
Thermomechanically controlled processed | Softest condition for deep forming, spinning or subsequent solution treatment; low strength and only moderate conductivity if Cr is partly in solution. | 100 | 250 | 40 | 55 HB | 55 % IACS |
hot forged, solution treated and aged | Forged electrode caps, mould inserts and large blocks where TH tempers are impractical; properties near TF00 with some section-size scatter. | 290 | 400 | 22 | 115 HB | 80 % IACS |
TF00Default Solution heat treated and precipitation hardened | The standard stocked condition: best balance of ~420 MPa strength with >80 % IACS conductivity — the classic RWMA Class 2 resistance-welding electrode temper. | 315 | 420 | 22 | 125 HB | 82 % IACS |
Solution heat treated and cold worked, full hard | Cold-drawn hard bar/wire supplied for later ageing or for uses where conductivity is secondary to strength. | 345 | 400 | 12 | 110 HB | 45 % IACS |
TD01 and precipitation hardened | Slightly cold-worked and aged strip/rod when straightness and modest strength gain over TF00 are wanted with good conductivity. | 345 | 435 | 20 | 128 HB | 82 % IACS |
TD02 and precipitation hardened | Intermediate step-aged temper when a little more strength than TF00 is needed but some bending ductility must remain. | 385 | 455 | 18 | 135 HB | 81 % IACS |
TD04 and precipitation hardened | Highest-strength wrought temper: use for heavily loaded electrode shanks, contact arms and switchgear pins where >430 MPa yield is required. | 440 | 495 | 14 | 150 HB | 80 % IACS |
What is QCr0.5?
QCr0.5 is a chromium copper equivalent to C18200, a precipitation-hardening high-conductivity copper supplied as bar, forgings and strip in M, TB00, TD04, TF00 and TH tempers. It combines 82 % IACS and 324 W/m·K with 315 MPa yield, 420 MPa tensile, 22 % elongation and 125 HB, and resists softening to about 400 °C, which is why it is standard for resistance welding electrodes and current-carrying structural parts. Fusion welding is difficult and locally over-ages the alloy, and machinability is moderate (score 45); C15100 is the alternative when conductivity outranks strength. QCr0.5 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,070°C (1,958 °F). QCr0.5 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 67% of copper alloy grades. Elongation at break is 22% and the elastic modulus is 117 GPa (17 Msi).
What is QCr0.5 used for?
- Welding electrodes
- Switch contacts
- Rotor bars
- High-conductivity fasteners
Advantages
- High service temperature — 400°C (752 °F), better than 97% of copper alloy grades
- Conducts heat well — 324 W/m·K (187.2 BTU/hr·ft·°F), better than 85% of copper alloy grades
- High electrical conductivity — 82 % IACS, better than 85% of copper alloy grades
QCr0.5 properties
Typical room-temperature values for QCr0.5-TF00; bars are the position among copper alloy grades.
Physical3
QCr0.5 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,070°C (1,958 °F).
Mechanical13
QCr0.5 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 67% of copper alloy grades. Elongation at break is 22% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
QCr0.5 is rated for continuous service to 400°C (752 °F). It conducts heat at 324 W/m·K (187.2 BTU/hr·ft·°F), better than 85% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
QCr0.5 conducts electricity at 82 % IACS, better than 85% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of QCr0.5 takes about 55 MJ of energy and emits 3.8 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
QCr0.5's machinability is fair (45/100, better than 64% of copper alloy grades); weldability poor (30/100); formability fair (45/100).
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. QCr0.5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with QCr0.5
Is QCr0.5 easy to machine?
Gummy in the solution-treated state — machine in TF00/TH tempers with sharp positive-rake carbide, high speed, light feed and flood coolant; expect roughly a quarter of free-cutting brass throughput.
Can QCr0.5 be welded?
Fusion welding is difficult (very high conductivity, tenacious Cr₂O₃ film) and locally over-ages the alloy; prefer GTAW with high preheat-free high current and argon, or use brazing/mechanical joints and re-age if strength matters.
Can QCr0.5 be formed, bent or molded?
Form, bend, spin or upset in the TB00/M condition, then solution treat (~980 °C, water quench) and age 2–4 h at 450–480 °C for full properties.
QCr0.5 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 |
|---|---|---|
| CrGB/T 5231 QCr0.5; C18200 range is 0.6–1.2 | 0.4 – 1.1 | 0.65 |
| Siimpurity limit | ≤ 0.1 | |
| Feimpurity limit | ≤ 0.1 | |
| Pbimpurity limit | ≤ 0.05 | |
| Znimpurity limit | ≤ 0.05 | |
| Cubalance, ≥98.6 % including Ag | balance |
What surface finishes work on QCr0.5?
Not anodizable; use bright dipping, chemical passivation, or Ni/Ag/Cr electroplating — silver plating is common for contact surfaces, and heavy plating bakes must stay below the ageing temperature.
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 QCr0.5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- C18200
How much does QCr0.5 cost?
QCr0.5 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.
QCr0.5 — frequently asked
What is QCr0.5 used for?
QCr0.5 is typically used for welding electrodes, switch contacts, rotor bars and high-conductivity fasteners. In short: softening resistance to 400 °C; standard welding-electrode copper; 82 % IACS with strength.
What is the yield strength of QCr0.5?
QCr0.5 has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 67% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is QCr0.5 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Gummy in the solution-treated state — machine in TF00/TH tempers with sharp positive-rake carbide, high speed, light feed and flood coolant; expect roughly a quarter of free-cutting brass throughput.
Can QCr0.5 be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is difficult (very high conductivity, tenacious Cr₂O₃ film) and locally over-ages the alloy; prefer GTAW with high preheat-free high current and argon, or use brazing/mechanical joints and re-age if strength matters.
What surface finishes work on QCr0.5?
Not anodizable; use bright dipping, chemical passivation, or Ni/Ag/Cr electroplating — silver plating is common for contact surfaces, and heavy plating bakes must stay below the ageing temperature.
Can QCr0.5 be formed, bent or molded?
Form, bend, spin or upset in the TB00/M condition, then solution treat (~980 °C, water quench) and age 2–4 h at 450–480 °C for full properties.
What is the maximum service temperature of QCr0.5?
QCr0.5 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 QCr0.5-TF00 and QCr0.5-TB00?
TF00 is the default condition — the standard stocked condition: best balance of ~420 MPa strength with >80 % IACS conductivity — the classic RWMA Class 2 resistance-welding electrode temper. TB00: supersaturated, soft and ductile — pick when the part must be formed or machined before precipitation ageing. Yield strength is 315 MPa in TF00 versus 90 MPa in TB00.
How much does QCr0.5 cost?
QCr0.5 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 B187/B187M Copper Bus Bar, Rod and Shapes — ASTM (2020)
- CDA Alloy C18200 Chromium Copper datasheet — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties of Copper and Copper Alloys — ASM International (1990)
- RWMA/ANSI Resistance Welding Electrode Material Classes (Class 2) — AWS/RWMA (2016)
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.