Knowing the bevel angle

[Southbound1]

Hey all,
I had a ZY laying around, that forgot about that I found yesterday. I bought it 2 years ago to us as a practice razor when stropping when I first started straight shaving. I was anxious about trying my new stones out so me being a newbie and all. The first thing I did was use Slashes method with a beltsander. I thinned the spine out and moved the hollow grind further up the spine.

So far so good. I kept the blade cool and didn't burn the temper.I didn't remove the scales though, that will come later, i was just itching to experiment, plus I don't have any pins or rods for repeening yet. Anyways before I progress farther is like to know what my bevel angle is currently . I don't know if I'm far enough or too far?? I do think its important to know what your bevel angle is at times.

They are a few good sources/formats on calculating the bevels Slash's spreadsheets, also one over on the coticle forum, and Jerod (superior shave) made a video. Don't poke to much fun of me! Lol I don't have enough sense to use the darn things! Right now I don't have any digital caliper yet. I do understand how to measure the blade correctly. Like so: Measure spine thickness, then measure from (the top of the "hone line bar" down to the end of edge/apex.) How do those calipers measure in mm or cm? Hundredths, or thousandths? Even If I did have calibers, they wouldn't do me anygood, because I don't know how to use those spreadsheets, and calculator's. The spine is just a hair over 3/16" or to be technical its exactly 6/32". From the top of the hone line down to the edge is exactly 11/16" Help would be appreciated.
Thanks
Mike

 

[eKretz]

15.7° based on your dimensions. Take half the spine thickness and divide it by the distance from the apex to the top of the hone wear on the spine. Then take the inverse sine of your result and double that to get your included angle. So:
[sin–¹(.094"/.688")] x 2 = 15.7°

A caliper normally measures in .0005", .01mm or both, depending on whether it's a mechanical dial caliper or an electronic digital.

 

[Southbound1]

15.7° based on your dimensions. Take half the spine thickness and divide it by the distance from the apex to the top of the hone wear on the spine. Then take the inverse sine of your result and double that to get your included angle. So:
[sin–¹(.094"/.688")] x 2 = 15.7°

A caliper normally measures in .0005", .01mm or both, depending on whether it's a mechanical dial caliper or an electronic digital.

Hey man!
I wish I knew how to use those spreadsheets! Looks like I went a little to thin! Is the sweet spot 16.5°?

 

[eKretz]

Yeah I don't know anything about the spreadsheets, I just use trig, lol. Generally a good angle to shoot for in my experience is between 16° and 18° - go too low and durability may suffer. I'd give it a go where you're at and see if the edge holds up. If not, add a layer of tape when finishing to form a secondary bevel at a more obtuse angle.

 

[Southbound1]

Yeah I don't know anything about the spreadsheets, I just use trig, lol. Generally a good angle to shoot for in my experience is between 16° and 18° - go too low and durability may suffer. I'd give it a go where you're at and see if the edge holds up. If not, add a layer of tape when finishing to form a secondary bevel at a more obtuse angle.

Im at a loss there. Lol I dunno trig, thats for sure! I do know I used a little too much pressure based on the spine wear, and larger bevel. Im glad these kind of razors are available for us newbies.

 

[Clay S]

Im at a loss there. Lol I dunno trig, thats for sure! I do know I used a little too much pressure based on the spine wear, and larger bevel. Im glad these kind of razors are available for us newbies.

As another option, you might use tape while bevel setting, and then recheck the measurements. If correct, re-bevel without tape. Provided spine doesn't change 0.675" is your target (about 43/64" or 17.15mm) that's for 16 degrees.

0.655" would be 16.5 degrees (16.64mm 21/32")

 

[bluesman 7]

15.7 degrees is close to perfect IME. If you're new to straights just hone with a piece of tape which will add a degree to the angle. If you're new to honing, honing with tape is a good thing anyway. When you can hone without quickly wearing through the tape then you can decide whether you want to use tape or not.

 

[Southbound1]

15.7 degrees is close to perfect IME. If you're new to straights just hone with a piece of tape which will add a degree to the angle. If you're new to honing, honing with tape is a good thing anyway. When you can hone without quickly wearing through the tape then you can decide whether you want to use tape or not.

Pressure when honing? I definitely used to much pressure. I read somewhere last night high pressure is just like the same amount of pressure you'd use when erasing a pencil mark from paper. So do I lighten up with each stone?

 

[Southbound1]

Oh well, I was hand sanding the ZY razor and accidentally bumped the toe against the table, and I cracked the blade. I just placed an order on 5 GD 66. Probably a month wait.

 

[global_dev]

look up wood magnetic sanding jig if you havent seen one. it’ll help protect from this.

 

[Slash McCoy]

Most razors will support a 15.7deg bevel angle okay. I gotta say, you had to take off a lot of steel to get a ZY that skinny! As for the shave, I don't think you will notice much difference between 15.7 and 16.5, if at all. There are other factors that are a lot more important than less than a degree of bevel angle difference.

Try it again. It is worth the effort.

 

[RobbyRobinson]

Regarding bevel angle, if the bevel angle is too high would that cause a more blunt edge that might still shave and require a higher shaving angle? Or would a more acute angle cause this?

 

[bluesman 7]

Bevel angles in excess of 20 degrees will still shave. Many people claim that they shave just fine. Personally I have always found angles above 18 to be meh. Yeah, they shave but.....

Regarding shave angle, yes I would agree that a more obtuse edge seems to require a higher shave angle, and a more acute edge seems to allow a flatter shave angle.

 

[bluesman 7]

By the way, a quick and dirty angle calculation can be done by Spine thickness/Active width X 57.3 =...

This can easily be done with pencil and paper without a calculator, computer, or trig tables. With a calculator it's very quick

The 57.3 comes from 360/2pi. This method is not mathematically 'correct', but at these small angles the mathematical error is insignificant and probably smaller than our measurement inaccuracies.

 

[RobbyRobinson]

Bevel angles in excess of 20 degrees will still shave. Many people claim that they shave just fine. Personally I have always found angles above 18 to be meh. Yeah, they shave but.....

Regarding shave angle, yes I would agree that a more obtuse edge seems to require a higher shave angle, and a more acute edge seems to allow a flatter shave angle.

Thank you my GD shaves smooth but requires a higher angle to shave and wont pop hairs