We have multiple windchimes, and had raccoons knock one off of the hanger and the strings broke when it crashed down onto our deck. Other chimes string we had were worn through from age.
Found this replacement string from an actual windchime company (Woodstock) and ordered the type of string according to the top diameter size as suggested.
Shipping was a bit high ($10 for a lightweight poly envelope?) but overall it was worth it due to knowing it was the right string to use (VS guessing elsewhere.)
Watched the how -to string videos, and mimicked the process.
Having two people helps, as well as first marking in pencil on the wood where the old string comes up and then out of the top board for each tube (1-1...2- 2...etc.) to know which hole to come up through and go down again for each length of pipe for hanging balance at the end.
We used a large -eye needle from an upholstery sewing kit we had.
The needle is KEY ! It can't be too thick, or it won't pass through the small holes in the wood. It can't be the curved kind of needle, unless one bends it somehow straighter. Thinner needles often don't have a large enough eye to thread the string through. (Too bad the company doesn't include the correct needle with the string, or at lest sell the right needle.)
Also, to save on string use, once everything is laid out on the floor and strung together lightly, knot the very last piece end good and pull the string more taunt (not too tight) along each section back to the beginning again, pulling excess string as you go. Then clip and secure the final end. ( Hope that makes sense.) More string is left for other repairs.
We used tiny sharp tacks pounded with a small hammer to hold the string in place (our chimes had those already) so no staples were needed.
Worth getting for about any brand of windchime to replace the string. Our chimes should last another 5-7 years now. ( We take in the repaired chimes each night now so no raccoons can get into mischief with them)