greetings y'all
recently i took an old simonds file and turned one end (no teeth at this point) into a knife, or started to. to make a long story short after forging and rough grinding and heat treating i decided i wasn't real satisifed with the results. so i went and broke it. call it destructive testing. i got 2 breaks, 1 started at the edge the other at the spine. upon close examination (looking at it through the wrong end of
10x50 binoculars (i think i owe alvin for that tip)) each starting point for the cracks seemed to have oxidation colors. the grain under that magnification looked similar to sugar under the naked eye perhaps 1/2 or 2/3 that size. what i'm wondering is is this a reasonable grain size or is it too large? if it is large what can i do different? i'm judging temps by color and quenched in water. for quenching i dunked the blade at bright red / maybe starting to glow orange. for tempering i used a torche to draw the spine to blue which resulted in straw/bronze at the edge. i've got another blade forged but not heat treated (did anneal it) that i like much better. before i heat treat it and recommendations? would it be better to use oil and if so will peanut oil work (have a couple of gallons on hand).thanks in advance.