Rookie Mistake

[edgarspencer]

Cocked, or un-cocked, Hammer springs are still under compression. The safest procedure would be to fully relax the spring by removing it.
Simple Green, while perhaps environmentally friendly, is still caustic, as are all citrus based cleaners. I would suggest it's best left in the garage, for cleaning engines. While it will simply remove paint (completely) at room temperature, it becomes even more potent at elevated temps.
Lock springs are made from a very high carbon steel (Ironically called spring steel) Making the material bend 180 degrees, even when heated cherry red, opens up edges on the outside of the radius. The best springers will carefully grind and polish the springs after bending, and tempering. Lesser quality springs probably don't get this skilled attention.

[Double Play]

Originally Posted by edgarspencer

Making the material bend 180 degrees, even when heated cherry red, opens up edges on the outside of the radius. The best springers will carefully grind and polish the springs after bending, and tempering. Lesser quality springs probably don't get this skilled attention.

Edgar,
I agree with everything you said but it dose not explain why this spring broke in the location that it did.

[edgarspencer]

The kinetic energy is stored along the entire spring. From the bend, to the stirrup hook, they are tapered, so that the energy is progressive. (High Performance springs in competition cars are called Progressive Springs) Any minute defect (As John stated, called a stress riser) along the surface can cause a failure when the spring is compressed.
It is blasphemy to say this, but visually compare the lock springs of our beloved Parkers to the spring in a "Best Grade" English gun, and it will be immediately evident the attention paid (or not) to these little bits. 'Theirs' look they're polished to a fairthewell compared to 'ours'.

[Eldon Goddard]

Is this true even for a high grade parker hammer? Do you think an A grade hammer gun would have polished springs? I have heard this from someone before so I am holding out hope that at least the high grade parkers stood up to the English best.

[edgarspencer]

Eldon, my highest grade hammer is a grade 3, and it's springs aren't polished very much. Brad Bachelder needs to ring in on this as he is messing with these for our dedicated hammer gun guys on a regular basis.

[edgarspencer]

Dean, I would agree that the heat didn't play a part in this from a metallurgical point, as it would need to get above about 900 degrees F, the lower critical temperature for alloy steel, but I think if the case can be made that the cleaning agent played a part, the heating of that agent would most likely intensify the etching effect.