Trial & Error or Evidence of the Crime

[cheftjcook]

What do you think of the remains/ evidence of my trial & error
of making a knife from a file.
I thought it was going so well, It was quenched not yet tempered,
I was cleaning up the blade, NOT thinking and tried to tweak it...SNAP!!!
I remind myself, A Lesson learned is not wasted time!
Make me feel better, who else has evidence of those
"Lesson Learned pieces" to Share
TIM

[Woody]

When high carbon steel has been quenched and before it is tempered it is EXTREMELY hard and EXTREMELY brittle the state is called "glass hard" for a reason it will break with the slightest provocation just like glass. Blades should be tempered immediately after quenching. Also when making knives out of files be sure you grind all the teeth off the file first otherwise they will produce cold shuts when the blade is forged and make it even more prone to breakage.

Woody

[HWooldridge]

Like Woody said, there is a great deal of stress in hardened, untempered steel. Some years ago, I was still getting a few plow sharpening jobs and did some on the 25lb LG for an old farmer who lived near us. When I got to the end of the pile, he asked to do the last sweep so I obliged. He did a pretty good job of sharpening but then quenched the sweep at a dull red into the slack tub. He pulled it out and was inspecting the edge, when the sweep went POW! and flew into several shards, one of which cut him and drew blood. Scared the s@#$ out of both of us but proved that forged and quenched high carbon is pretty unstable.

[RagTag]

I had the same thing happen to a student during a punch and chisle making class. 1/4 inch square punch of high carbon iron. Student quinched at dark red and you could hear the tinkle of the steel. I warned him not to quinch too hot. He held it up and it slipped out of his tongs and popped when it hit the ground. Put a pair of metal chips in his calf. Ouch!