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.
The Smell of Molten Projects in the Morning 
Sears is a department store, so their brands (including Kenmore) are built by various other manufacturers (often slightly tweaked from the name brand versions). The first three digits in the model number encode the real manufacturer. There are a lot of lists out there, but 158 is a tricky one to find. It turns out that it was made by Maruzen, which is, unsurprisingly, a Japanese company. Today they’re known as Jaguar and are on the web at http://www.jaguar-net.co.jp if you’re curious.
Mary found a table of Sears sewing machine manufacturers that included Maruzen, but I’ve obviously been remiss in omitting the full model number. This 158.17032 bears a family resemblance to the others in our stable by Mazuren, while featuring completely different mechanical bits in many places.
They’re all well-made and, given somewhat more care than some folks apply, should last pretty much forever.