They’re typically screwed onto the underside or inside of wooden furniture, boxes, frames, or wooden joints to reinforce a weak or cracked area. The curved shape lets them bridge a joint while the countersunk holes hold them securely with screws.
The small round pieces may be matching reinforcement washers/plates from the same type of hardware.
So, in short: they’re hardware used to strengthen or repair wooden joints and furniture. 🔩🪵
