Hand Tools Archive

question- more details

Bill Tindall, E.Tn.
Subjectively, I like XHP a little softer than the two new irons are (those are tempered at 375 degrees and are a little hard mannered. I'm not going to duration test every iron that I make, but I doubt they'd go much longer than the mule (which is probably 60 hardness or so, maybe ever so slightly higher) and the mule is twice as easy to sharpen.

The 2 latest one's were tempered at 375 vs ?? for the original. Are you saying the two newest blades are harder?... (because?) ....And they are more resistant to abrasion in sharpening by 2X(estimated?)?

And you are speculating that in spite of the fact that these blades are 2X more difficult to sharpen by abrasion that they will last the same amount of feet when planing? Because they will chip? Or are you speculating that they will last so long you don't want to face testing them ;)

Only a few thousand feet separate us from some fundamental knowledge on the effect of hardness on edge life. >(

If they are too hard you will see chipping. Easy to test. Use them like a chisel and chop some end grain with each. Your dandy microscope will readily reveal if the edge is micro deforming or chipping.

Next visit one of your local machine shops and get some hardness data.

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