Thread: Chipping after shaving HRC issues? Custom Razors

This is a long story and im going to start from the top just so everyone knows the big picture to get your thoughts!

i have been making my own blades for the last 2 years and havent had a bit of issues with edge retention after shaving and never had to worry about rockwell testing... I recently purchased a slab of 52100 and been working with it. i finished 5 razors and all of them went right along as all my blades have, i got them to their final edges which went fine as well... i shaved with the razors and i found chipping all over the blade... i then checked the razor after stropping the next time just in case it was bad technique there, still chipped after shaving with the razor, all 5 did the same thing.... i got the blades tested and they were 55-58 HRC which i thought was too low and this was my issue... i then gave up on the 52100 and got me some 01 tool steel, i made 6 razors and only final ground 1 just to test prior to doing the rest of the blades... sure enough the edge was chipping after shaving! i just went to get all my 01 tool steel razors tested and had them range from 59-61 HRC the blade in question was 59-60.... So now im pretty sure thats hard enough but whats causing this issue?!

Here is how i am HT'n my blades... i got the 52100 up to 1675 quench in peanut oil that was at 150 degrees... tempered the 52100 back to 425 2 cycles on the first batch... the second i tempered back to 375 2 cycles ... both had issues...

the 01 i normalized in 3 cycles and quenched at 1550 then i tempered those blades to 350 2 cycles...

now there are a few things i am thinking is the issue...

1st of course is im grinding way too hot ruining the temper of the blade... i thought this but i really dont get this blades all that hot, really im talking 1-2 pass then dip.... takes a long time but ive always been that cautious.... still i plan on making a make shift coolant with an IV drip when i go home and grind tonight...

2nd i think the rockwell testing isnt correct because they are testing the shank of the blade when its the edge that really matters... i am going to ask about testing the edge of these blades rather than the shank

3rd i dont know if this is possible but i wondering if i am grinding the edge way too thin... i dont think this is it but maybe?


i have taken the blades to a local heat treat and they will be working these 52100 blades for me... i am hoping that fixes it


Anyway i know its been a while since i posted here and i really look forward to using the plethora of knowledge here to see your thoughts and what to do to alleviate!

Thanks,
Fonz