A very thorough introduction, Ben.  Glad you put this together for us.  I have experimented with larger or wider secondary bevels on thin axes and have found in my wood they cut well and hold up over time better.  When I get down under 18 the steel starts to take on damage on most axes, but with a stouter secondary bevel they hold up.  And since the main bevel is the most important I’m not sure the size of the secondary bevel matters that much under 18 degrees.  But obviously we’d all prefer to use a razor blade if we could.  If only trees grew without limbs lol.

I just found your channel.
I consider myself a bit of an expert, who has done some bushcraft, owns a selection of axes, and knows his stuff.
A few videos in and I'm starting to worry that I am like one of those tourists who buys an expensive camera and thinks he must automatically be a photographer.
You are incredibly skilled, VERY good at explaining your craft, and I consider myself humbled. Thank you mate.

This has to be one of the best explanations I’ve seen. Well made video sir. I’ll be watching this a few times.

Clearly one of the best videos on the subject, the diagrams are great!! Makes me want to file some axes once again just to be sure of my angles 😁

This is a great treatise on axe geometry.

For the local woods and the use I put my axes through, an angle between 20 and 25 degrees with no secondary bevel or microbevel seems to work best. I made a few wedgy hatchets and put 23 degree "flat" grinds on them, along with convex cheeks and they never get stuck in anything. They throw a good chip, too.

This is the only quality video on the internet clearly explaining the subject. Thank you so much 🙏🏽

Good, concise explanation of good geometry. Lots of axe restorers who otherwise do very good work are still grinding their axes with cringe-worthy, obtuse bevels just to apex and call it finished. Nicely restored axes with terrible geometry are so prevalent that I had to unfollow most of the axe pages I used to follow on IG.

Great video, you can tell how much work went into this. It was definitely worth it!

Really nice video Ben! I enjoy the videos you’ve been putting out. Not many take the time to explain and put a science to these things. Thanks for the diagrams. Really cool stuff👍

Really good video on axe geometry! Especially liked the virtual part!

This is the finest presentation on this subject I have seen.
Great video thank you Ben!

Thank you! One of the best informational / instructional videos I've seen.
As a Blacksmith / bladesmith I'll put this information to work.

Excellent video with fantastic graphics. Thanks for putting it together.

I like a very high, full convex on all my edges. Knives too! the basque axe works so well, because of convex grinds.

This is a very thorough, interesting, simply explained and informative video. I have just ordered a couple of metal files!

Well done explanation. I like convex edges but they have to be done with thinner cheeked axes and the bevel on the convex needs to be steep. A short, fat, obtuse, convex edge geometry is quite bouncy and only good for splitting.

Great informations thanks, again.

Great information here!  I think that about sums it up.  Thanks!

Fantastic education right here.  Thanks, Ben!