Blade Sharpness Research Project

[Space_Cadet]

@helicopter

Look what I've found:

 

[helicopter]

This is Sotraco's Lord Super Stainless patriot blade in a 5 blade tuck. It is a standard thickness blade, mild in sharpness, with good balance, and fair durability and consistency. Performance suggests a platinum driven metallic coating despite nomenclature that would conventionally indicate an absence of metallic coating.

It is a three stage grind with some large stria from using crude abrasives. The coating is sloppy. In the second photo, taken after the test, we see that the failure mode of the steel is lots of large chipping and some denting typical of Sotraco and inexpensive low-quality blade steel in general.

Performance doesn't closely align with other Sotraco blades tested so far. My guess is that this example, with its good balance, is close to the nominal specification, which seems to take some luck with Sotraco. The street price of this blade is around $8/100. At that price, the performance is completely uncompetitive. You can get vastly superior Chinese blades for half of the price.

Date	5-Jan-2025			Blade Thickness, mm	0.100
Blade	Sotraco	Lord	Super Stainless P5	Egypt	13-Nov-2021
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	16	8	26	26	25
Median F (g)	56	51	56.5	58	74
Mean F (g) Top	54	51	68	70	79
Mean F (g) Bottom	62	52	58	58	72
Mean F (g)	58	52	63	64	76
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	75	71	94	97	110
Avg. Adj. F (g) Bottom	86	73	81	80	100
Median Adj. F (g)	78	70	79	81	103
Mean Adj. F (g)	81	72	87	89	105

Blade Sharpness Test Index

 

[catchacoolbreeze]

I can think of possible reasons your Treet Classic tuggs less than your Voskhod on the second pass. Batch variation is one possibility. Treet has a fairly clean grind categorization, so I doubt you got sharp Treet Classics, but you may have gotten dull or damaged Voskhods. It could be your beard, if it is exceptionally hard on blades, is damaging the Voskhod in the first pass. It could be the coatings are behaving differently with your face and software. The thicker and tougher edge of the Treet blade may just behave better, being less flexible at the apex. I wonder if you would have a different impression using a razor with less gap and exposure. I don't think your experience with these two blades is typical, but I don't find it too surprising either. There are a lot of factors that affect sharpness of two individual blades, and there are several factors other than sharpness that might be effecting how the blades feel when you shave with them.

Those seem all viable. In my quest to find good blades, I am just trying to figure out how I can use the information that you are gathering for a possible benefit for me. Perhaps it could also benefit others.

You mentioned that the Treets have a "clean grind categorization" and a "thicker and tougher edge" - What does that exactly mean, how are you determining those things? Is there a way to find blades with similar "grind" characteristics and similar "edge profiles"? Even if its just a subjective characterization, it may be helpful?

Maybe I missed it but would you be willing to make some of the data people would use to sort blades available in a read-only google sheet so we can sort in some way. For those that only use a blade once, it would be also interesting to see what the ranking would be of sharpness as new. If the blade doesn't get past the first shave, I'm not keeping it for the second or third.

No worries either way as I am sure is a lot of work.

 

[catchacoolbreeze]

Some more anecdotal info. I also have in my notes that Astra Blues and Wizamets felt tuggy to me as well but they rank well on the scale and sharper than Treet Classics.

Interestingly also, is that a lot of people claim Feather AC blades are the sharpest blades (or some of the sharpest) out there but none of them passed a hanging hair test for me. They also felt dull to me every time I have used them. They rank dull on your ranking despite convectional "wisdom" - which is great to see. So some of my experiences mirror your testing.

Who would have thought edge sharpness could be so complex?

 

[helicopter]

Those seem all viable. In my quest to find good blades, I am just trying to figure out how I can use the information that you are gathering for a possible benefit for me. Perhaps it could also benefit others.

You mentioned that the Treets have a "clean grind categorization" and a "thicker and tougher edge" - What does that exactly mean, how are you determining those things? Is there a way to find blades with similar "grind" characteristics and similar "edge profiles"? Even if its just a subjective characterization, it may be helpful?

Maybe I missed it but would you be willing to make some of the data people would use to sort blades available in a read-only google sheet so we can sort in some way. For those that only use a blade once, it would be also interesting to see what the ranking would be of sharpness as new. If the blade doesn't get past the first shave, I'm not keeping it for the second or third.

No worries either way as I am sure is a lot of work.

The cutting force wear curves of Treet blades tested fall into clean buckets making a stair-step chart, because their processes are well controlled. It follows that a typical Treet blade will perform close to the nominal specification, and it makes it easy to identify which grind specification they used for the model.

They don't have any grinds that are very sharp, because all of their specifications are for bigger angles at the apex.

Since grinds are done in stages at different angles, and my scalable images all show the side of a flat blade, I can't calculate the angles, but I can get a general idea by looking at thicknesses and bevel heights.

Voskhod is definitely more acute at the apex than any of the Treet blades, which should translate to more bending and flexing, and less plowing straight through.

Such publicly available Google Sheets do exist, but it is against forum rules to put the links here or mention the place where the links are published.

There is a zip file with an excel sheet higher up the thread that @BigAlVista updates and posts.

If you want to find blades similar to the ones you like, one strategy is to expand the big chart at the end of the most recent test, look at the blade you liked, and see if there are blades nearby with similar curve shapes. You could look up the tests in the index link there, and see if the test indicates a blade you might want to try.

 

[helicopter]

Some more anecdotal info. I also have in my notes that Astra Blues and Wizamets felt tuggy to me as well but they rank well on the scale and sharper than Treet Classics.

Interestingly also, is that a lot of people claim Feather AC blades are the sharpest blades (or some of the sharpest) out there but none of them passed a hanging hair test for me. They also felt dull to me every time I have used them. They rank dull on your ranking despite convectional "wisdom" - which is great to see. So some of my experiences mirror your testing.

Who would have thought edge sharpness could be so complex?

You could look at standard deviation in the test summary chart. That shows how much the sharpness varies from location to the next. If it varies a lot, then there will be some spots that are below the average sharpness. Those duller spots will certainly tug first, especially if they represent big chips or dents.

Eventually I plan to quantity smoothness using something like this, though it will be more sophisticated than just standard deviation. AI, which is very good at solving problems like putting a number on smoothness or tugginess, tells me I will probably want to use different formulas for each stage of the test, and that seems like a good way to do it.

I think there is probably a better way to express the centrality of the sharpness than averages, too, but averages are good enough for now, while I am focused on testing, and averages are easy to understand.

I still have more blades to test before I get into that, though. The plan is to test more, then clean up data table into something AI can manipulate very effectively, and then come up with some more analysis techniques. A lot of what is not reflected in the charts of averages has still been measured and is there in the data.

 

[catchacoolbreeze]

The cutting force wear curves of Treet blades tested fall into clean buckets making a stair-step chart, because their processes are well controlled. It follows that a typical Treet blade will perform close to the nominal specification, and it makes it easy to identify which grind specification they used for the model.

They don't have any grinds that are very sharp, because all of their specifications are for bigger angles at the apex.

Since grinds are done in stages at different angles, and my scalable images all show the side of a flat blade, I can't calculate the angles, but I can get a general idea by looking at thicknesses and bevel heights.

Voskhod is definitely more acute at the apex than any of the Treet blades, which should translate to more bending and flexing, and less plowing straight through.

Such publicity available Google Sheets do exist, but it is against forum rules to put the links here or mention the place where the links are published.

There is a zip file with an excel sheet higher up the thread that @BigAlVista updates and posts.

If you want to find blades similar to the ones you like, one strategy is to expand the big chart at the end of the most recent test, look at the blade you liked, and see if there are blades nearby with similar curve shapes. You could look up the tests in the index link there, and see if the test indicates a blade you might want to try.

To the content in bold - This is becoming more interesting. In my shave notes, I use a word like "pop" where the sensation is the blade just plowing straight through as you say and popping off hair effortlessly. It's the same sensation I get when I use a heavy grind straight razor which has considerably less flex than something hollow ground. It's the best feeling and something I have been chasing. I always thought it had to do with sharpness for DE blades because they are all so thin compared to the body/edge of a straight razor. But maybe these small nuances in bevel angle, even in a really thin and flexy DE blade can give you that clean cutting "pop" feeling.

I will have to look at your pictures to see what I can discern. Like you said, the pictures are of a flat blade so I am not exactly sure what I am looking for but I'll try to give it a go this week. Thanks again for the other info as well.

 

[LRod]

Interestingly also, is that a lot of people claim Feather AC blades are the sharpest blades (or some of the sharpest) out there but none of them passed a hanging hair test for me. They also felt dull to me every time I have used them. They rank dull on your ranking despite convectional "wisdom" - which is great to see. So some of my experiences mirror your testing.

I also haven't felt them to be that sharp. To me the sharpest AC blades are the Schick Prolines.
At least that's how they feel anyways!

 

[geneaut]

@helicopter

Look what I've found:

View attachment 1971760

I used a different Diplomat last week. I suspect these were made in the Personna plant in Israel, but I don't have any proof of that beyond the wrappers being the same as other blades I have from that plant.

 

[helicopter]

I used a different Diplomat last week. I suspect these were made in the Personna plant in Israel, but I don't have any proof of that beyond the wrappers being the same as other blades I have from that plant.

View attachment 1972140

That's the one I just tested. It is definitely a Nazareth blade. Not just the wrapper. It has the Star of David on it. Is the tuck like mine, or is it the one that says the packaging is made in England?

 

[geneaut]

That's the one I just tested. It is definitely a Nazareth blade. Not just the wrapper. It has the Star of David on it. Is the tuck like mine, or is it the one that says the packaging is made in England?

I'll try to double-check the tuck tonight, and report back.

The first two shaves on it were nothing to write home about. Shave number three was a nice shave.

 

[helicopter]

This is Sotraco's Lord Platinum primary from a 5 blade tuck. It is moderate in sharpness with fair balance, durability and consistency. I believe this example is a reasonably good representation of the specification.

The scratches are not coarse, but they are uneven. There is a visible metallic coating. In the second picture we see that the failure mode of the steel was some medium chipping.

Performance is pretty close to the other Lord Platinum that is not labeled as "new" on the tuck, so I think they are probably both made to the same specification and both good examples of that specification.

Date	6-Jan-2025			Blade Thickness, mm	0.090
Blade	Sotraco	Lord	Platinum Primary 5	Egypt	1-Mar-2021
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	13	11	16	30	23
Median F (g)	48	47	48.5	55.5	57
Mean F (g) Top	44	54	50	59	59
Mean F (g) Bottom	55	45	52	74	66
Mean F (g)	49	50	51	67	62
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	61	75	69	82	82
Avg. Adj. F (g) Bottom	76	63	72	103	91
Median Adj. F (g)	67	65	67	77	79
Mean Adj. F (g)	69	69	71	93	87

Blade Sharpness Test Index

 

[helicopter]

This is Sotraco's Lord Platinum in a red tuck of six blades packaged for the Malay Archipelago markets, and I believe it is made to the same specification as the primary color tuck version measured in the previous test.

The grind looks the same as the other one, but this one held up better to testing, with a failure mode of small chipping and denting.

I couldn't get a 90 micron measurement on this individual, but I suspect it is made from 90 micron stock like the other one, but warped.

Date	6-Jan-2025			Blade Thickness, mm	0.093
Blade	Sotraco	Lord	Platinum Red 6	Egypt	1-Jan-2024
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	7	9	8	24	17
Median F (g)	54.5	49	50	48.5	51
Mean F (g) Top	51	49	54	62	60
Mean F (g) Bottom	56	50	49	41	48
Mean F (g)	54	50	51	51	54
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	71	69	75	86	84
Avg. Adj. F (g) Bottom	78	70	67	57	67
Median Adj. F (g)	76	67	70	67	71
Mean Adj. F (g)	75	69	71	71	76

This blade is included in the charts for the prior test above, so I won't post them again here.

Blade Sharpness Test Index

 

[pjgh]

This is Sotraco's Lord Platinum in a red tuck of six blades packaged for the Malay Archipelago markets, and I believe it is made to the same specification as the primary color tuck version measured in the previous test.

View attachment 1972280 View attachment 1972281

The grind looks the same as the other one, but this one held up better to testing, with a failure mode of small chipping and denting.

View attachment 1972282 View attachment 1972283

I couldn't get a 90 micron measurement on this individual, but I suspect it is made from 90 micron stock like the other one, but warped.

Date	6-Jan-2025			Blade Thickness, mm	0.093
Blade	Sotraco	Lord	Platinum Red 6	Egypt	1-Jan-2024
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	7	9	8	24	17
Median F (g)	54.5	49	50	48.5	51
Mean F (g) Top	51	49	54	62	60
Mean F (g) Bottom	56	50	49	41	48
Mean F (g)	54	50	51	51	54
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	71	69	75	86	84
Avg. Adj. F (g) Bottom	78	70	67	57	67
Median Adj. F (g)	76	67	70	67	71
Mean Adj. F (g)	75	69	71	71	76

This blade is included in the charts for the prior test above, so I won't post them again here.

Blade Sharpness Test Index

Alternative/new packaging for what was the Lord Tajam, perhaps?

... which contain that self-same sleeve with 'New' Platinum wording and the self-same Platinum Super Stainless blade. Either way, it's the platinum partner for the Lord Cool.

 

[helicopter]

Alternative/new packaging for what was the Lord Tajam, perhaps?

... which contain that self-same sleeve with 'New' Platinum wording and the self-same Platinum Super Stainless blade. Either way, it's the platinum partner for the Lord Cool.

Yes. I ordered Tajam (from RBC) and received the red Platinum.

 

[helicopter]

This is Sotraco's Lord Asco Platinum Super Stainless orange blade. It is a moderately sharp 95 micron blade with good balance, and typical durability and consistency. Performance is fairly good for a Sotraco blade, and I believe this individual is a good representation of the specification.

It has a typical Sotraco three stage grind with errant stria from uneven abrasives, and uneven transitions. In the second photo, taken after the test, we see that the failure mode of the steel is some small chipping. This looks like one of the better examples of a Sotraco blade.

It must be the same grind as Asco SS red, but with a platinum coating added, which increases durability and consistency, and gives it a J-Shaped sharpness wear curve typical of platinum driven metallic coatings. Performance is similar to the new red 90 micron Lord Platinum that replaced the 90 micron Lord Tajam in the Malay archipelago, and also to the Lord Crown Platinum. I suspect the alloy, grind, and coatings are the same on all three, and that the entire specification is the same as the Crown Platinum.

The street price of this blade is $8/100. I don't recommend it as there are blades from more consistent manufacturers at that price point.

Date	8-Jan-2025			Blade Thickness, mm	0.095
Blade	Sotraco	Lord Asco	Platinum Orange	Egypt	7-Sep-2022
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	10	7	9	12	16
Median F (g)	55.5	50	47.5	47.5	47.5
Mean F (g) Top	56	48	50	51	54
Mean F (g) Bottom	58	52	46	47	50
Mean F (g)	57	50	48	49	52
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	78	66	69	71	75
Avg. Adj. F (g) Bottom	80	72	64	66	69
Median Adj. F (g)	77	69	66	66	66
Mean Adj. F (g)	79	69	67	69	72

Blade Sharpness Test Index

 

[helicopter]

This is Sotraco's Lord Big Ben Classic Super Stainless tigers blade. It is 95 microns, mild in sharpness, with typical balance, durability, and consistency.

It has a typical Sotraco three stage grind with errant stria from uneven abrasives, and uneven transitions. In the second photo, taken after the test, we see that the failure mode of the steel is some small chipping. This is also one of the better examples of a Sotraco blade.

It is probably related to the Lord Classic SS, or the Lord Crown SS, but there is too much variance in the samples to draw a good hypothesis about it.

I think that covers Sotraco blades and Egyptian blades available in normal US retail pipelines. Let me know if I missed one.

Date	8-Jan-2025			Blade Thickness, mm	0.095
Blade	Sotraco	Lord Big Ben	Classic Tigers	Egypt	9-Aug-2016
Wear on Edge	0	3	6	9	12
Edges Measured	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top	Bottom / Top
Measurement Medium	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21	Stren 4 .21
Dulling Substrate	New	Paper	Paper	Paper	Paper
Measurements	20	20	20	20	20
Adj. Std. Dev.	9	11	16	21	29
Median F (g)	51	59	56.5	59	68.5
Mean F (g) Top	50	53	62	73	86
Mean F (g) Bottom	55	59	54	56	61
Mean F (g)	52	56	58	64	73
BESS Adj. Factor	1.39	1.39	1.39	1.39	1.39
Avg. Adj. F (g) Top	69	73	86	101	119
Avg. Adj. F (g) Bottom	77	82	75	78	84
Median Adj. F (g)	71	81	79	82	95
Mean Adj. F (g)	73	77	81	90	102

Blade Sharpness Test Index

 

[pjgh]

I concur from my entirely subjective face-feel testing that the Asco and the Crown (both platinum and stainless) feel very similar and this appears to be borne out in the empirical data. The Tajam, though, I'd say is far more like the Superior Platinum (blue/yellow sleeve) ... which I think you noted in the (new Tajam) Platinum analysis @helicopter.

I had rather formed a general theory that all the blades of each type (stainless, chrome or platinum) were the same, regardless and any difference was in the manufacturing variance and/or human element on the day but there does appear to be some intentional differences. Nevertheless, with that in mind even my face-feel testing thought there to be some difference.

Keep 'em coming @helicopter ... I'm quite the Lord fan! In fact, using different Lords for my daily shaves at the moment.

 

[pjgh]

I think that covers Sotraco blades and Egyptian blades available in normal US retail pipelines. Let me know if I missed one.

Actually, yes, I think you've got 'em covered!

Racer branding has a platinum, actually my preference of all the platinums but doubt there's actually that much in it. Big Ben Platinum, too. There is also Blue Sword Extra (one I have not actually tried) and guess it would be akin to the Lord Extra. Rixos is another branding I've seen. There's also a carbon steel offering - the Captain, probably discontinued. I have had the pleasure of shaving with the Captain and it was okay ... but not a patch on Treet carbon blades.

RBC used to carry them: Captain - Razor Blades Club - https://www.razorbladesclub.com/razorblades/captain/

Rixos

... Turkish market? Possibly private branding for Rixos Hotels?

 

[ButterfaceX]

Thanks Helicopter for all your hard work, fantastic information, dedication, drive & passion! And so much more...
Truly Appreciate All You Do!

Now I was in Utah, just for two days from my job.
And ran into this on Google while I was out there (clean shaved & bored in the hotel ).
Cultandking.com website, in Utah...
Seems like some hype and marketing, but thought you & others may get a kick from it.
-------------------------------------------------------------------------------------------

ULT+KING® Platinum DE (Double Edge) Safety Razor Blades Box of 100.

A dream-come-true blade that offers up a near-perfect combination of sharpness and smoothness, with high consistency from blade to blade.

Forged with the finest stainless steel, then platinum-coated with micro precision edges for the smoothest of shaves for any skin or beard type.

These highest quality blades fit ALL standard double edge safety razors. Each blade is individually wax paper wrapped, then paper wrapped, and then packed in a sealed box of five blades. Twenty five-blade boxes are in each 100-blade box. Blades easily snap in half with fingers for insertion into most standard shavettes.

Save the planet while you save your face from razor burn. Highest Quality stainless steel, platinum coated, micro-precision edges. Universal blades fit all standard double edge safety razors. Good for the master barber or the beginner. Simple paper packaging is environmentally friendly.

Single-blade shaving is better for your skin, better for the planet and more economical.

We took the best razor blades in the world and added an amazing laser-printed design, because why not? We want to be sure you don’t mistake our blades for anyone else’s.

--------------------------------------------------------------------------------------------


All I could say is ...Why?

BFX