Description of π Copper Bright Silver Tinned Diameter: Ensuring Brilliant Conductivity and Durability
Suitable for uninsulated wiring and electrical grounding wire use. Greater than 99 percent pure copper. Uninsulated single-strand wire with tin plated coating. Meets QQ-W-343 Type S standards for uninsulated copper wire. Meets ASTM B3 standards for annealed copper wire and complies with RoHS regulations.
Tinned wire is more expensive but lasts longer when exposed to salt, chemicals etc. than bare copper wire. Haven't used enough to see if there are any problems with the coil, but on the outside it was fine.
I've used these wire as part of my art for years and they never disappoint. It's flexible enough to be manipulated and shaped, yet very durable and suited my needs. I prefer the smaller 16 ounce reels over the very large multi pound spools. They are delivered quickly and are available in different sizes.
This wire has a nice thick coating of tin which allows it to be twisted with notched pliers without exposing the copper underneath. Tinning makes it very easy to solder (these days I use tinned wire wherever possible if I plan to solder it). Basically there is what you expect from the description.
Pros
Highly rated by testers for strength and durability