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The goal of this page is to research the different copper sheet options provided by McMaster-Carr and to provide a recommendation.
Multipurpose 110 Copper
“Offering high electrical conductivity and formability, 110 copper is 99.9% pure. Also known as ETP copper, it's often used in electrical applications, such as for bus bars and wire connectors, as well as for flashing, gaskets, and rivets.” [1]
Softened (Annealed) Temper Sheets
o “annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable.” [2]
o Annealed copper sheets are more ductile, and thus increasing forming capabilities. This would be useful when bending the busbars.
o Typically, around 10,000psi Yield Strength
1/8 to 1/4 Hard Temper Sheets
o H00 Cold-Rolled 1/8 Hard and H01 Cold-Rolled, high yield 1/4 Hard
o “H-series tempers are designed to produce materials with specific quantities of stress-relieved, cold work and cold-worked (drawn) tempers, HR-tempers, order-strengthening tempers and HT-Tempers by cold working.” [3]
o Around 20000psi (1/8 hard) and 28000psi (1/4 hard) for Yield Strength
o Essentially these sheets are stronger, requires more force to yield/bend
1/2 Hard Temper Sheets
o Similarly, these sheets are stronger and harder
o Yield Strength: 37,000 psi
Mirror-Like Multipurpose 110 Copper Sheets
“Polished on one side to a reflective, mirror-like finish, these sheets come covered with a protective peel-off film.” Yield Strength: 36,000 psi, Hardness: Rockwell B40 (Soft), Temper: H01 (1/4 Hard)
Probably don’t need reflective sheets, mostly aesthetic
Brushed Multipurpose 110 Copper Sheets
“One side of these sheets has a brushed finish with grain lines running in one direction to mask fingerprints. The brushed side comes covered with a protective peel-off film.” Yield Strength: 36,000 psi, Hardness: Rockwell B40 (Soft), Temper: H01 (1/4 Hard)
Also probably don’t need brushed sheets, mostly aesthetic, also have to remove a peel-off film
Super-Conductive 101 Copper Sheets and Bars
“With 99.99% copper content, 101 copper has higher purity than 110 copper, resulting in superior electrical conductivity.” [1]
Softened (Annealed) Temper Sheets
o Yield Strength: 10,000 psi
o Hardness: Rockwell F65 (Soft)
o Temper Rating: Softened (Annealed)
Also comes in 1/8, 1/4, 1/2 hard
101 vs 110
From McMaster-Carr:
101 is 99.99% copper, 110 is 99.90%, 101 offers superior electrical conductivity.
But how much more conductive is 101?
From McMaster-Carr both 101 and 110 have the same surface resistivity and thermal conductivity (10.3 Ohms, 226 Btu/hr. × ft./°F @ 68 ° F) when annealed.
Other sources have 101 and 110 at the same electrical conductivity rating of 101 (% IACS at 68F (20C) annealed.) [4] [5]
Both have similar yield strengths when annealed
101 slightly more expensive
For a 12”x12”x0.062” sheet:
110 is $54.34
101 is $62.99
They come in different thicknesses, 110 has a greater selection of choices, do we have a preference for thickness?
Busbars modeled as 1.5mm thick in CAD, 1.5mm ~ 0.06”
Final Recommendation
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Links
[1]https://www.mcmaster.com/copper-sheets/
[2] https://en.wikipedia.org/wiki/Annealing_(materials_science)
[3] https://www.nationalbronze.com/News/what-the-temper-designations-of-copper-alloys-really-mean/
[4] http://www.quantumalloys.com/data/electronic/alcopper.html