Back in the days before Aeroquip and the other fancy tubing choices we have today, low pressure lines were commonly rubber hoses secured with hose clamps. in order to make sure the hoses don't slip off, the tubing they were attached to, you needed beads. This is the tool that every aircraft mechanic needed back in the old days. When Earl's supply was a storefront on Hawthorne Blvd, I walked in and there was a pile of these in the front window for $25 each. Should have bought a lot more than the one I did.
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