Each tooth's head is wider than its neck. Closed, every head hooks behind its two neighbors across. The slider is the only thing that can bend them apart.
Teeth hooked
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Opening at the top
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Teeth per side
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Head vs. neck width
0.54 vs. 0.36 pitch
Teeth on the two sides alternate. Each head sits in the neck gap between two heads across.
Pull the tapes sideways and the heads catch on each other. Press Tug apart to try it.
A head can only slip out when its row bends. Bending fans the heads open, like spreading fingers.
The slider's curved channels bend each row 34° at a radius of 1.7 teeth. The diamond holds the rows apart above that.
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