I learned this in the 70s, so who knows if I remember it right, but I think quenching hardens it & letting it cool naturally anneals it or leaves it more flexible. For the last couple inches of a fish tape it may not matter.
Re: Broken fish tape#69277 09/03/0601:06 AM09/03/0601:06 AM
A Blacksmith replies: Fish tapes are made from high carbon (spring) steel for strength and are sold hardened and tempered to be pretty stiff. That's how they work, you are pushing a long spring through the conduit. The heating to cherry red (not in bright light) allows you to bend the tape into a big loop for attaching wires or a tight one to contain a nut for attachment of a leader of some type. The material will then hold the loop (with minor adjustment) for a long time but if you attempt to bend the hardened steel you risk breaking it under strain. So let the tape air cool naturally and you will have a new end that will hold up.
Re: Broken fish tape#69281 09/04/0607:39 PM09/04/0607:39 PM
BigB: Couple of incidents, actually. Presence of mind is a slippery thing some days, I don't work around the big stuff alone anymore. I was staring into a 2,500 A 480 V CH switchboard with the outer cover removed. My hands were resting on a horizontal edge of the dead front with one piece of a cast copper bus tap (meanwhile the SWEPCO guy had left to get his hot stick and kill the transformer)and was just about to touch this 2 pound chunk of copper to the energized bus with both wrists on the grounded dead front...My journeyman saw what I was about to do, yelled "IT"S HOT!!" and grabbed my shoulder, pulling me back from a scenario that I was 1/2 inch away from that would have really messed up my weekend. The second incident involved installing an automatic capacitor bank on top of a switchboard. The only logical mounting location was above an 8,000 A terminal section, where this gob of cables came into the building from the transformer and fed both ways into 4,000 A Mains. What a mess of bus bars, lugs and cable. I had the top to the 2 piece front off and was working on a stepladder, securing the capacitor unit to the S/B structure, when I dropped a 5/8 x 3 bolt with a couple of washers on it, into the open section...yes, Virginia, your life does flash in front of your eyes as I awaited the fireball. The spaces between the phases were pretty narrow and all I can say to the incident was that Devine Intervention saved my scrawny behind from being toast. It seemed like minutes passed before the hardware clattered to the bottom on the enclosure. That was more than 10 years ago and the incidents provided the impetus for me to become a blacksmith. But the bidness of Blessing Wires pays better, so I am back at it. I B Lucky...