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

I am by no means any sort of hardening expert, but many blades i have seen were HRC65.

I think if the edge was ground too thin, you would have cracking and honing issues...

Originally Posted by dinnermint

I am by no means any sort of hardening expert, but many blades i have seen were HRC65.

I think if the edge was ground too thin, you would have cracking and honing issues...

yeah i was just reading around on the forum and found people having razors that were 55 HRC and were fine with them... the hardness of this blade doesnt sound like the issue here... of course unless im mistaken about 55 HRC being okay...

I'm leaning toward over heating during final grinding its just i really dont grind them hot so it surprises me...

What angle are you at ??

What about if your issue has nothing to do with the making but the finish and honing. Bear with me for a background theory. You can damage steel below the surface. That is how they can use acid to recover removed serial numbers. So what if your chipping is done by something you do in your final prep of the blade. Like doing the initial bevel set with a somewhat course diamond hone. Or maybe the material on your finish belt on your grinder. There are a ton of variables. What comes to mind is two years in and this problem pops up. What else have you changed?

Have you tried to hone with more than a layer of tape?
Do 2 or 3 layers fix the problem?

Originally Posted by gssixgun

What angle are you at ??

Originally Posted by mainaman

Have you tried to hone with more than a layer of tape?
Do 2 or 3 layers fix the problem?

i see what ya'll getting at... i really thought i was at a good angle for what i was making but this is definitely out of the box thinking i was looking for! so many many moons ago i was given a standard, and that standard was to make 8/8 blades with 1/4 steel 7/8 7/32 steel and 6/8 in 3/16... so i dunno what angle that makes it but the rule of thumb is that... should i still go home and throw 2 layers of tape and give it a go or is that angle good?

Originally Posted by RezDog

What about if your issue has nothing to do with the making but the finish and honing. Bear with me for a background theory. You can damage steel below the surface. That is how they can use acid to recover removed serial numbers. So what if your chipping is done by something you do in your final prep of the blade. Like doing the initial bevel set with a somewhat course diamond hone. Or maybe the material on your finish belt on your grinder. There are a ton of variables. What comes to mind is two years in and this problem pops up. What else have you changed?

exactly! 2 years and never had this issue! i use better belts that's for sure! im setting the bevel with a worn out 400 atoma.... aside from that alot of the ways i grind my razors and everything are pretty much the same... not change at least from what i can remember...

Originally Posted by Dafonz6987

i see what ya'll getting at... i really thought i was at a good angle for what i was making but this is definitely out of the box thinking i was looking for! so many many moons ago i was given a standard, and that standard was to make 8/8 blades with 1/4 steel 7/8 7/32 steel and 6/8 in 3/16... so i dunno what angle that makes it but the rule of thumb is that... should i still go home and throw 2 layers of tape and give it a go or is that angle good?

You lose nothing by trying 2 layers. If the edge holds then you have two variables to figure out only,: 1. how wide to make the blade for the spine thickness you are at to increase the angle and avoid chipping. 2. The HT might be off, although chipping does not occur at low hardness. You should see problems with edge holding and bevel setting if you HRC is too low.

What is was getting at is if you recently changed your belt from one model to another. Like you just started using zircon belts or a ceramic. There was a thread not that long ago about makers discussing that time saved using a diamond plate to the initial bevel set did not always save time because it sometimes causes chipping. These are other possible areas you can look for solutions. Try setting the bevel with an 800 grit hone.