Thread chaser kits were tested against damaged, rusty, and JB Weld-covered bolts to see which tools can actually repair threads without destroying them. Brands including Lang Tools, Vevor, CTA, Orion, ...

Actually, it seems to be a composite material, not sure if it's plastic. Someone was a bit too heavy for a chair here at work and cracked the seat. It's a $1200.00 chair, so I saved it from the trash.