I have a couple of blades which I am making, I am curious whether the hardening and tempering process I have done has worked and how accurately so. Does anyone know of a person or company I can send a selection of blades to to be checked for hardness?
Testing rockwell hardnness
- Thread starter ledders666
- Start date
Hardness is only one factor in the quality of the heat treat. Something that reads in the low 50's RC can still snap easily if you have large grain size.
But if you are looking to just read hardness, then the files mentioned are pretty good for a 'ballpark' figure. They are fairly subjective but once you get used to them they can give you an idea within 2 or 4 points how hard something is. They work on any exposed bit of metal and the level of surface finish is less important. Also a set only costs about £40
A proper hardness tester will give much more accurate readings obviously, but surface prep is more important. The test piece must be flat and parallel sided and needs to be finished to at least 400grit with no oil or dust on the surface as these will cause duff readings (to the point that it can read 10RC out!). If you can meet the prep parameters and pay return postage, then I'm more than happy to do some hardness tests on my machine if you like
But if you are looking to just read hardness, then the files mentioned are pretty good for a 'ballpark' figure. They are fairly subjective but once you get used to them they can give you an idea within 2 or 4 points how hard something is. They work on any exposed bit of metal and the level of surface finish is less important. Also a set only costs about £40
A proper hardness tester will give much more accurate readings obviously, but surface prep is more important. The test piece must be flat and parallel sided and needs to be finished to at least 400grit with no oil or dust on the surface as these will cause duff readings (to the point that it can read 10RC out!). If you can meet the prep parameters and pay return postage, then I'm more than happy to do some hardness tests on my machine if you like
good advice thank you, I will bear that in mind for future,
The part about paralel sides, how would that work for a knife as the shape is not paralel?
The part about paralel sides, how would that work for a knife as the shape is not paralel?
all you can do is to take a reading from the ricasso or tang, assuming that they are flat and parallel Since few of my blades have those features I stick a test block in with the blades when I do the heat treating. The blocks are close to the thickness of the blades to give as close a match in hardening effects as possible (thin sections also give false readings, so testing a 1mm strip is not good either)
Since few of my blades have those features I stick a test block in with the blades when I do the heat treating. The blocks are close to the thickness of the blades to give as close a match in hardening effects as possible (thin sections also give false readings, so testing a 1mm strip is not good either)Similar threads
