Online Metals Copper Protobox 20 lb - Assorted Shapes – Pure Copper Sheets, Rods, Plates, Stock Tube, Pellets for Crafts, Jewelry, and Scrap Metal, Random Copper Pieces for DIY and Industrial Projects

A box of copper offcuts is either a joy or a headache, depending on what you need from it. After spending a few weeks working through the Copper Protobox, I land firmly in the “joy” camp. It’s a 20‑lb grab bag of pure copper in sheets, rods, plates, tubes, and the occasional pellet. If you like solving problems with what’s on the bench, it’s a surprisingly capable way to keep useful stock on hand.

What you actually get

My box arrived well packed and a hair over the advertised 20 lb. Inside was a genuinely useful spread: thin and mid‑gauge sheet, a few short plates, several rod and tube cutoffs, and a handful of small bits that work as shims, inlay, or test coupons. The shapes are random, but not random in the “unusable scrap” sense. Most pieces were long enough or broad enough to become parts, not just practice fodder.

Expect some surface oxidation from storage and handling, saw-cut ends, and occasional burrs. Edges clean up quickly with a file or a quick pass on a belt sander. Nothing I received looked like plated base metal; magnet check was negative and the bright finish came right up after a Scotch-Brite pad or a dip in a mild citric acid solution.

Material quality and purity

This is sold as 100% pure copper. In practice, offcuts like these are typically ETP copper (C110), which machines and forms well and offers excellent electrical and thermal conductivity. My DC resistance checks on a few machined bars lined up with C110 expectations. For general fabrication, jewelry, heat-spreading, and electrical bus work, the material quality is right on the mark.

If you need oxygen-free (OFHC) copper for vacuum work or very specific grain/oxygen content for lab use, assume you won’t have traceability here. There were no heat numbers or grade stamps on my pieces. For most workshop and craft applications, that’s not a deal-breaker.

Working the stock: cutting, forming, and joining

• Cutting: Bandsaw, hacksaw, shear, and cutoff wheel all worked fine. Rod and tube cuts stayed square with light feed pressure to avoid grabbing. Sheet sheared cleanly down to small strips.
• Machining: With sharp tooling and generous cutting fluid, copper machines cleanly. Keep speeds moderate to avoid smearing or built-up edge. Drilling was uneventful; step drill worked nicely on tube.
• Forming: Anneal if you’re doing tight bends—bring to a dull red and quench. The sheet pieces took a planished curve beautifully for simple jewelry cuffs and decorative escutcheons.
• Joining: Soft solder flowed easily with a non-corrosive flux. For heavier sections, silver braze is my preference; TIG brazing with silicon bronze filler also worked for structural tabs. Traditional copper welding is possible but not what this assortment is best for.
• Finishing: Scotch-Brite, fine files, and 600–1200 grit paper produced a quick brushed sheen. Liver of sulfur and ammonia fuming patinated predictably for jewelry accents. Clear lacquer or wax slows re-oxidation.

What I built and why this box helped

• Bus bars and ground links: Short flat bars became low-profile bus bars for a bench DC supply. Drilled, countersunk, and stacked, they beat waiting for cut-to-length copper online.
• Heat spreaders and shims: Plate offcuts made perfect thermal bridges under a high-power LED module. Thin sheet supplied shims for a machine vise without raiding feeler gauges.
• Jewelry experiments: A couple of sheet strips became hammered cuffs, and rod offcuts turned into rivets and pins. The variety lets you try techniques without overcommitting to full sheets or long bar.
• Electroplating anodes: Rods and plates served as sacrificial anodes in a small copper plating setup. Consistent performance, easy to shape to fit the tank.
• Garden markers and inlay: Thin sheet cut into tags (stamped with a letter set) and small inlay tiles for a walnut box lid. The patina on outdoor pieces is a feature, not a flaw.

The common thread: the assortment nudged me into making do with what I had, and that speed matters—no quoting, no minimum orders, just grab a suitable piece and get it done.

Where it shines

• Variety with intent: The mix leaned toward actually usable sizes. Having both hollow tube and solid rod on hand is handy—tube for lightweight spacers and bushings, rod for pins and terminals.
• Value for prototyping: Buying one-off, cut-to-size copper is pricey. A mixed box amortizes cost across many small projects, fixtures, and experiments.
• Teaches good habits: Sorting, labeling thickness/diameter, and keeping a cut bin makes the next project faster. This box kickstarts that ecosystem.
• Conductivity and heat work: For anything that needs to move electrons or heat—test leads, lugs, heat sinks, fixtures—the material is exactly what you expect copper to be.

Trade-offs and limitations

• Randomness cuts both ways: You might wish for more solid stock or thicker plate and get more tube and thin sheet instead. If your next project needs a 1/4" x 2" flat bar at a specific length, don’t count on it being in the box.
• No grade traceability: If your spec demands OFHC or certified C110 with documentation, this won’t satisfy QA.
• Surface condition varies: Expect tarnish, shop scuffs, and the odd saw mark. If you need pristine mirror surfaces, plan on time at the disc or send out for finishing.
• Food-contact caveat: Copper conducts heat wonderfully, but bare copper isn’t ideal for acidic foods. If your plan includes grilling skewers or cookware components, know the safety considerations and finishes.

Tips to get the most from it

• Sort on day one: Caliper everything, write sizes with a paint pen, and set up bins for sheet, plate, rod, and tube. You’ll save hours later.
• Keep joining supplies handy: A good flux, 60/40 or lead-free solder, and a silver braze kit open up a lot of assemblies. For TIG brazing, silicon bronze filler is friendly here.
• Anneal strategically: If a bend feels springy or starts to crack, anneal. Copper rewards proper heat treatment.
• Build a fixture library: Use small offcuts to make soft jaws, soldering fixtures, and heat spreaders you’ll reuse across projects.
• Protect the finish: Wipe down after handling; a thin microcrystalline wax film keeps fingerprints and oxidation at bay.

Who it’s for

• Fabricators and maintenance techs who need ad‑hoc bus bars, lugs, and heat spreaders without waiting on a PO.
• Hobbyists and makers who like to prototype in metal and value a stocked scrap rack.
• Jewelers and metalsmiths looking for practice stock and small runs without buying full sheets or long bars.
• Educators running plating demos, conductivity experiments, or simple forming/annealing labs.

If your work lives on prints with tight purchasing specs, or you’re producing repeat parts that demand consistent stock dimensions, a box like this is the wrong tool. Order cut-to-size instead.

The bottom line

The copper Protobox is exactly what I want in a shop “consumable”: real material, in practical shapes and sizes, at a reasonable cost, ready the moment an idea or repair pops up. It won’t replace a proper material order for a defined project, and the luck-of-the-draw nature means some boxes will align with your needs better than others. But as a general-purpose copper cache, it’s been far more useful than I expected.

Recommendation: I recommend the Protobox to anyone who values flexibility and keeps a project queue. The assortment is thoughtfully usable, the material quality is solid, and the cost-to-utility ratio beats piecemeal purchasing for small builds, fixtures, and experiments. If you need guaranteed sizes, certified grades, or perfectly uniform stock, look elsewhere; for the rest of us, this is a smart way to keep 20 lb of capability within arm’s reach.