tail spring re-arch

[SkyPirate]

Jim the springs used for tail wheels now a days are made from what is called "Blue Tempered Spring Steel" its not the true high carbon spring steel still used in trucks etc ,..don't heat it you will activate the atoms burning off what carbon is in it making it soft,,if you quench it it will become brittle

added: its better to bend a tail wheel spring then break it,..same with most of the light duty trailer springs,..they will bend before they break on most newer applications

[avidflyer]

You bend the spring cold. Unless you know how to retemper spring steel to the right amount. I know the spring shop I talked to bends theirs cold as well. Another point of interest, if you are making up a new spring and need to drill holes, don't drill a pilot hole and then try to drill the right size larger hole. Drilling the spring work hardens it and you probably won't be able to drill the larger second hole. That advice also came from the spring shop. I didn't try to prove them wrong. It's best to use a drill press so you can drill at a slower speed with plenty of pressure, maybe use some cutting oil as well. I would use a new sharp drill bit as well. If you don't make it through in the first attempt, the second try will probably be worse. Jim Chuk

[SkyPirate]

very true Jim, drilling it does the same heats it up work hardening it which will also make it brittle at the sides of the hole , when I use to extend a tractor trailer frame or add a frame rail I used a magnetic drill with a low RPM drive ..it would take 20 minutes to drill a 1/4" thick wall no fluid..just sharp slow turning bit

[n85ae]

I've had no troubles drilling holes in leaf springs, just takes cutting lube, a
sharp bit and pressure. I drilled mine last year with my drill press, no problems
at all. I always drill a pilot hole, and work my way up in sizes until the final
size is achieved.

Jeff

[SkyPirate]

Musta been the new lower carbon Blue Tempered Spring Steel

[jiott]

Is there a good way to tell if its the "Blue tempered spring steel" or the old "Hi carbon spring steel"?

[SkyPirate]

Do a search for a grind chart, usually higher carbon is a white spray of sparks where low carbon it orangeish spray, take a grinder and grind an edge a with it, doesnt take much to determine

[SkyPirate]

http://www.weldguru.com/metal-composition.html

[SkyPirate]

The spark metal composition test is a method of classifying steels and iron according to their composition by observing the sparks formed when the metal is held against a high speed grinding wheel. This test does not replace chemical analysis, but is a very convenient and fast method of sorting mixed steels whose spark characteristics are known. When held lightly against a grinding wheel, the different kinds of iron and steel produce sparks that vary in length, shape, and color. The grinding wheel should be run to give a surface speed of at least 5000 ft (1525 m) per minute to get a good spark stream. Grinding wheels should be hard enough to wear for a reasonable length of time, yet soft enough to keep a free-cutting edge. Spark testing should be done in subdued light, since the color of the spark is important. In all cases, it is best to use standard samples of metal for the purpose of comparing their sparks with that of the test sample.



, you want to see a whiter with few orange sparks on spring steel

[charliehill]

here is the source of spark test from WIKIPEDIA.
https://en.wikipedia.org/wiki/Spark_testing
http://www.ylflux.com/