This steel strip emerged from inside the arm of the Kenmore 158.17032 sewing machine that we’ve been reconditioning for one of Mary’s friends:
The ends show the granular fracture of hard steel:
It’s 13.3 mm long, 1.0 mm thick, tapers slightly from 2.8 mm on the end that once said “Japan” to 2.76 mm on the other, and that’s all we know about it.
The sewing machine seems to work well enough without it (after some clean-and-lube action) and we haven’t found where the piece came from, but circumstantial evidence suggests it’s part of a spring somewhere inside the arm. It’s in a little bag with all the other random sewing machine parts I’ve collected along the way; perhaps some day we’ll know more and I can fabricate a replacement.