Thread: Chipping after shaving HRC issues? Custom Razors

This is the Google box calculation


(2 * asin(.181 / (2 * .620)) * 180) / pi = 16.786646


The red is the width of the spine the green is the height of the blade from where it touches on the hone... plug that into Google search and voila Math !!!


or let's just plug in your 6/8 calc figuring the height at .740 rather than .750 for the full 6/8 height...


(2 * asin(.188 / (2 * .740)) * 180) / pi =14.5956583

This is about 1.5° low from the accepted 16° target / average we found on Vintage razors, some razors target 17°

At 6/8 each layer of tape adds about .66° to the measurement so you need 3-4 layers to bring it into spec... HT Temper and Steel can absorb some of the variance but building razors to accepted spec makes life easier


This is why we are known around the internet as "Know it Alls" on SRP


ps: I only checked the 6/8 size you can play with the others and see where they come in at

Originally Posted by mainaman

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.

After u mentioned the tape I came straight home to one of the blades... I was really anxious and excited, had the problem I've been having really be as simple as bevel angle... immediately slapped 3 layers of tape and honed... edge was chippying... then i bread onifed the blade a bit and honed again... it was chipping... I went ahead and took pictures in hopes this would help....

Originally Posted by RezDog

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.

Thanks! Will do! Any suggestion works!

Originally Posted by gssixgun

This is the Google box calculation


(2 * asin(.181 / (2 * .620)) * 180) / pi = 16.786646


The red is the width of the spine the green is the height of the blade from where it touches on the hone... plug that into Google search and voila Math !!!


or let's just plug in your 6/8 calc figuring the height at .740 rather than .750 for the full 6/8 height...


(2 * asin(.188 / (2 * .740)) * 180) / pi =14.5956583

This is about 1.5° low from the accepted 16° target / average we found on Vintage razors, some razors target 17°

At 6/8 each layer of tape adds about .66° to the measurement so you need 3-4 layers to bring it into spec... HT Temper and Steel can absorb some of the variance but building razors to accepted spec makes life easier


This is why we are known around the internet as "Know it Alls" on SRP


ps: I only checked the 6/8 size you can play with the others and see where they come in at

I don't take someone educating me as someone acting as a know it all... I am always open to anyone's suggestions as I wasn't born with all the knowledge on how to make razors, so educate away

On another note I'll have to wait for my math queen to come home and teach me what ur showing me �� Never been the best at math

How are you heat treating your blades? The reason I ask is that I have a digitally controlled electric kiln and I added a thermocouple temp probe and was shocked be the temp variation on the screen, it was 20 c off where the razors were sitting so I now have temp probes measuring in three different zones just to be sure. Also 1550f seems way to high for 01 that's about 843c and if your probe is off it could be way higher, I harden my blades at 805c for example.
Also have you snapped one of you blades or a test piece to have a look at the grain structure? That helped me a lot because I realised that something was off as I was getting chipping etc, so started looking at my heat treating procedure which once I mastered sorted it out.
Also another consideration is your tempering has to be spot on again you need precise temp control.
And as for blade angle I have found that it needs to be above 16 degrees or the edge can be too thin ,believe it or not some of my best shavers have been at 18-19 degrees.
Hope this helps a bit.
Ps there is a great bevel angle calculator on www.coticule.be it helped me tremendously as you can plan in advance how high your grind should be with the thickness of stock you are using for example everyone thinks that 1/4" stock is great for 8/8" but if you grind right up to the spine you are at around 14.3 degrees without tape which is no good and who wants to use 3-4 layers every time they hone not me!
Edward Brice

Originally Posted by Dafonz6987

After u mentioned the tape I came straight home to one of the blades... I was really anxious and excited, had the problem I've been having really be as simple as bevel angle... immediately slapped 3 layers of tape and honed... edge was chippying... then i bread onifed the blade a bit and honed again... it was chipping... I went ahead and took pictures in hopes this would help....



Thanks! Will do! Any suggestion works!

It is hard to tell without having the blade in hand, but it is possible you have not quite set the bevel yet?

Originally Posted by EdBrice

How are you heat treating your blades? The reason I ask is that I have a digitally controlled electric kiln and I added a thermocouple temp probe and was shocked be the temp variation on the screen, it was 20 c off where the razors were sitting so I now have temp probes measuring in three different zones just to be sure. Also 1550f seems way to high for 01 that's about 843c and if your probe is off it could be way higher, I harden my blades at 805c for example.
Also have you snapped one of you blades or a test piece to have a look at the grain structure? That helped me a lot because I realised that something was off as I was getting chipping etc, so started looking at my heat treating procedure which once I mastered sorted it out.
Also another consideration is your tempering has to be spot on again you need precise temp control.
And as for blade angle I have found that it needs to be above 16 degrees or the edge can be too thin ,believe it or not some of my best shavers have been at 18-19 degrees.
Hope this helps a bit.
Ps there is a great bevel angle calculator on www.coticule.be it helped me tremendously as you can plan in advance how high your grind should be with the thickness of stock you are using for example everyone thinks that 1/4" stock is great for 8/8" but if you grind right up to the spine you are at around 14.3 degrees without tape which is no good and who wants to use 3-4 layers every time they hone not me!
Edward Brice

I am using a kiln with a pyrometer, otherwise the kiln is analog lol... I broke one of my blades long ago and found a pretty nice grain structure, i actually was going to buy an upgraded kiln but after this whole fiasco I'm almost thinking against it... of course if the conclusion of all this is bevel angle then I may still get one lol

Originally Posted by mainaman

It is hard to tell without having the blade in hand, but it is possible you have not quite set the bevel yet?

Yeah I slept on it last night, I'm back at it again today... so I was thinking if I had a poor angle too acute of an angle to begin with how much would I need to bread knife off in order to get rid of it... maybe I'm over thinking it now, let me know what u think.... also I'll be trying again today...

Alrighty played around more with ur it yesterday, my wife went over it and explained the math to me. The razor that failed on me the first time all I needed was another piece of tape making it 4 and an angle of 17 instead of 16.

I then worked on the 8/8 blades and same thing, I actually turned it into a 7/8 and angle up to 17 and boom... in one sense I'm glad this was my mistake as I don't have to buy new kiln... but boy do I feel dumb, I remember being taught this stuff when I first started but I took that rule of thumb and figured I could leave it at that....

Well thanks gents thanks again! On the plus side since I was struggling to make these blades I now have 10 completed and 15 rough ground lmao... now time to go back to work

I would definitely get yourself a high temp thermocouple just so you can double check your temps, and as far as bevel angle you need to measure the thickness of the spine and also the measurement from the bevel to the the top of the grind line and plug it into the calculator on coticule.be and you will get the bevel angle, it also shows you what the angle will be with 1,2,3 layers of tape which is helpful.
In my experience you generally get a chippy edge when you have a high Rockwell hardness in conjunction with a really low bevel angle.
It's a bit like baking cakes eventually you will get your own recipe that works for you and your equipment and all will be good. Ed.

Originally Posted by EdBrice

and as far as bevel angle you need to measure the thickness of the spine and also the measurement from the bevel to the the top of the grind line and plug it into the calculator on coticule.be and you will get the bevel angle, it also shows you what the angle will be with 1,2,3 layers of tape which is helpful.
In my experience you generally get a chippy edge when you have a high Rockwell hardness in conjunction with a really low bevel angle.
It's a bit like baking cakes eventually you will get your own recipe that works for you and your equipment and all will be good. Ed.

The formula to calculate the angle was posted a few posts above and the OP already worked through the iterations.
Seems that he had success.