What is C110 copper? Electrical, art, and food uses

What is C110 copper?

C110 is electrolytic tough pitch copper, ETP for short: copper refined to at least 99.90% purity, with a trace of oxygen (about 0.02-0.04%) left from the refining process. It's the standard commercial copper in Canada. Buy copper bar or sheet off any rack in the country and C110 is almost always what you're holding.

The number that earns it the job: annealed C110 conducts at 100-101% IACS. IACS is the scale conductor metals are scored on, with annealed copper set at 100%, so C110 is the yardstick itself. Among metals you can actually buy, only silver beats it, and nobody racks silver bar.

The C110 that leaves our counter goes three ways: electrical work, art and architecture, and kitchen or bar builds. Each one has a catch worth knowing before you order, so here's all three, honestly.

Why is busbar made from C110 copper?

Because busbar is a conductivity job, and C110 is the conductivity metal. A busbar is a solid copper bar doing the work of a very fat wire inside a panel or between equipment. The material brief is simple: carry maximum current, drill and bolt cleanly, take a solid joint. That's C110 flat bar. The copper bar we stock is made to ASTM B187, the specification covering copper bus bar, rod, and shapes for electrical and general use. The same bar covers ground bars, bonding jumpers, and machined electrical fittings.

What we won't hand you is an ampacity table. How much current a bar can safely carry isn't a property of the bar alone. It depends on allowable temperature rise, spacing between bars, ventilation, joints, and the rest of the design. Size your bus to the Canadian Electrical Code with your electrical engineer or inspector. We'll supply the bar: the cross-section you spec, the length in inches, cut to ±1/8″.

Can you torch or braze C110 copper?

Yes, and most jobs go fine, but C110 has one real failure mode to understand before the flame comes out: hydrogen embrittlement. The trace of oxygen in tough pitch copper sits in the metal as microscopic copper-oxide particles. Heat the copper above roughly 400°C (750°F) in a hydrogen-rich atmosphere and hydrogen soaks in, finds those particles, and turns them into steam inside the metal. A fuel-rich torch flame counts as that atmosphere. So does a hydrogen furnace. The steam blows tiny voids along the grain boundaries, the copper turns brittle and can blister, and there's no fixing it afterward.

If your craft keeps a torch on copper (annealing between hammer passes, heat colouring), this caveat is for you. Keep the flame neutral to slightly oxidizing, never a soft fuel-rich feather. Work quick. The damage deepens with time at temperature. Pick lower-temperature silver solder over high-temperature brazing where the joint allows it. And if the work truly lives in a hydrogen atmosphere, that's the job oxygen-free copper grades exist for. We don't stock oxygen-free copper, but we can source it on request.

How does copper patina, and can you control it?

Bright salmon pink on day one, matte brown within weeks to months, deep brown for years, then green. That's the natural sequence, and the timing mostly depends on the air. The Statue of Liberty went up in 1886 penny brown and took about 20 years to finish turning green. Around Halifax harbour, salt air pushes copper through those stages years faster than a dry prairie town will see.

You don't have to wait, and you don't have to let it happen. Forced patinas are a craft of their own: heat for colour runs, sulfur compounds for browns and blacks, salt and ammonia fuming for greens and blues. Recipes vary and surface prep decides the result, so test on an offcut first, not on the finished piece. Want no patina at all? Polish the metal, seal it with clear lacquer or paste wax, and renew the seal yearly. Thin sheet is the usual canvas for patina work. A 9″ × 12″ piece of our .027″ C110 sheet runs $46.34 as of July 2026.

Is copper safe for food and drink projects?

Treat bare copper as reactive with food, because it is. Acidic food and drink (tomato, vinegar, citrus, wine) dissolve copper off the surface, and too much copper makes people ill. That's why the tradition for copper pots and mugs is a lining of tin or stainless steel between the metal and the meal. And to be plain about our lane: we sell raw C110 metal stock, not certified food-contact cookware.

Plenty of copper builds never touch the issue: a sealed bar top, a range hood, cabinet hardware, candle plates, planters. If bare copper will meet food or drink in your build, plan a proper lining or a coating rated for food contact. Selling the piece? Check your local food-safety rules before you commit to the run. We'd rather say that plainly than sell you sheet for a mug run that gets pulled at the market.

How do you form, anneal, and machine C110?

C110 forms beautifully and machines grudgingly. It's soft and ductile, but it work-hardens: every bend and hammer pass leaves it a little stiffer, and pushing on without a reset ends in cracks. The reset is annealing, and copper's version is easy.

Heat the piece to a dull red glow, about 400-600°C (750-1100°F), easiest to read in a dim shop. Then quench it in water or let it air cool. With copper the cooling speed changes nothing, which surprises people coming from steel. Quenching just gets the piece back in your hands sooner. Anneal between forming passes as many times as the job needs. Keep the flame neutral rather than fuel-rich, because hot tough pitch copper in a hydrogen-rich flame can turn brittle.

Machining is the honest weak spot. C110 rates about 20 on the machinability scale where C360 free-machining brass sets the 100 mark. It cuts gummy: long stringy chips, smearing, drill bits that grab. Sharp tools, slow feeds, and cutting fluid get a one-off part done fine. But if the part is mostly lathe and mill work and copper colour is all you need, machine C360 instead. Our 360 vs 260 brass guide covers that swap. If the part needs copper's conductivity, accept the gummy cuts and go slow.

What copper do we stock, and what does it cost?

One grade, C110, in the shapes copper jobs order: flat bar, round bar, sheet, square bar, and a bit of hex, all on the copper rack. Bar stock is made to ASTM B187. Pick a size, type your length in inches (sheet takes a width and a length), and the price shows up. Cuts are free to ±1/8″, volume discounts of 5-15% apply automatically, and prices update daily. Our Canadian metal price guide shows where copper sits against steel and aluminum as of July 2026.

There's a $40 order minimum. Order by 1pm Atlantic on a business day and your pieces are usually cut and packed the next business day, which is what normally happens, not a guarantee. How fast it lands after that is the service you pick at checkout. We ship up to 96″ a piece anywhere in Canada, and pickup in Dartmouth is free, usually ready within one business day. First time buying by the inch? Here's how cut-to-length ordering works. Need oxygen-free copper, a width we don't rack, or a 21 ft run? Send a quote request and we'll price it. Sourcing runs 2-21 days.