Thread: Sharpness tests

I have been honing a while but it seems hit and miss.
My question: are there any tests for sharpness that don't involve cutting arm hair? My arm hair doesn't cut easily. Using 1200 king to set bevel; I can barely cut arm hair. I then use the Norton 4/8K. Off the 8K the arm hair cuts easier, but never above the skin.

Is it necessary to use something like chromium oxide to finish a razor. Using stones doesn't give consistent results and at times not sharp enough.

Joe

Here's the section on Sharpness Tests from the Library.

When starting out with honing, I found the TNT (thumbnail test) to be the most beneficial for me. Also did arm hair tests but never any HHT charades. Eventually, I worked up to TPT (thumbpad test) when I finally decided I wouldn't let that one bug me.

I have been using the TNT for years.

Pete <:-}

SRP Library to the rescue:
https://shavelibrary.com/w/Sharpness_tests_explained

Simple

There is no one test for everyone

Try them all at each stage until one test becomes YOUR go / nogo never fail test then expand from there

+1 for thumbnail test. Though I don’t use it past bevel set. I use a loupe throughout the honing process, watching the water and the feel of razor on the hone can usually tell you all you need to know after the bevel set.

Like Glen said, figure out your own tests by trying everything. As you develop your honing skills you will figure out what works and what doesn’t, for you. Test shave your edges and pay close attention to what your tests look and or feel like before the shave, you’ll eventually get really good idea if the edge will feel god before the steel even touches your face.

Mark and Glen got it covered for ya.
You just need to know what works for you.
Above the arm, Hair test, or tree topping as its called, after finishing is a good one but it can tell you two things. One, You have microchips and it's pinching the hairs in half or two, you got an edge so sharp its finding the spot between the folicals and wedging them apart. (If that's the right word? I know its not spelled right.)
TNT at bevel set and TPT at finish plus a good loupe should tell you everything, but you need to know what its really telling you. And that takes practice. Non-consistency is normally from not enough practice. Keep at it and keep testing. You will find what works. Sure you can shave off an 8K, but I bet most of us would consider that a Pre-finisher.

I also use the thumbnail test for determining when the edge has arrived. From there, I use tactile feel on the stone and naked-eye observation augmented by an ~10x achromatic triplet loupe as to viewing chipping, scratch patterns, and relative polish. Sometimes, I also check to see if a few hairs are popping off the back of my hand towards the end of a honing progression, followed by the hanging-hair test after stropping. Otherwise, I've stopped checking via arm hair as I don't like walking around with patchy arms, particularly in summertime.

Originally Posted by Brontosaurus

I also use the thumbnail test for determining when the edge has arrived. From there, I use tactile feel on the stone and naked-eye observation augmented by an ~10x achromatic triplet loupe as to viewing chipping, scratch patterns, and relative polish. Sometimes, I also check to see if a few hairs are popping off the back of my hand towards the end of a honing progression, followed by the hanging-hair test after stropping. Otherwise, I've stopped checking via arm hair as I don't like walking around with patchy arms, particularly in summertime.

After the TNT at bevel set, I lean on an 10x achromatic triplet -- that is to say, an actual jeweler's quality loupe instead of an LED-festooned $5 pile of garbage from mainland China -- to keep tabs on progression progress and any unwelcome problems.

I cannot stress enough the tool quality difference between a typical Amazon $5 LED "poop-loop" and for example a BelOMO 10x achromatic triplet (< $40 usually but depends upon promos at the time of purchase).

If you don't mind viewing the world through a pseudo fog and feel like experiencing some minor eye strain, go China!

Agree with the folks above on the TNT. Nail that and the rest of the process is edge refinement and/or polishing. If you don't nail that, the rest of your efforts will be in vain.

I also use a test very similar to the one that Murray Carter promotes. I cannot in good conscience recommend it without caveats. It's a very good test but can also be very dangerous. Proceed with extreme caution.