DE Blade Thicknesses

[Esox]

I have 36 different DE blade types.

Since it was brought up in my journal thread I thought I'd take them to a friend who happens to be the head of Fleet Service for Greyhound Bus Lines and have him measure them with his Mitutoyo micrometer to .0001"

I'll copy paste my journal post here so it gets a wider audience.

______

Below you'll find 36 different blade types measured for thickness with a Mitutoyo micrometer to .0001". These measurements are not rounded to the nearest .0001", but are the actual, exact, measurements.

Sputnik - 0.0350
Derby Extra - 0.0400
Gillette Silver Blue- 0.0350
Polsilver SI - 0.0400
Wizamet Super Iridium - 0.0350
Gillette 7Oclock Sharp Edge - 0.0350
Gilletee 7Oclock Super Platinum - 0.0350
BIC Chrome Platinum - 0.0400
Shark Super Chrome - 0.0390
Feather - 0.0410
Gillette Rubie Platinum Plus - 0.0375
Superinox Bolzano - 0.0390
Gillette 7 O'Clock Super Stainless - 0.0425
Lord Platinum - 0.0425
Gillette Nacet Stainless - 0.0450
Rapira Platinum Lux - 0.0400
Perma Sharp Stainless - 0.0350
Treet Platinum - 0.0350
Shap Star - 0.0400
Persona Med Prep - 0.0400
Treet Platinum Super Stainless 0.0390
Persona Platinum Chrome - 0.0400
Shaverboy Super Stainless - 0.0450
Voskhod - 0.0400
Astra Superior Stainless - 0.0400
Astra Superior Platinum - 0.0350
Super Max Blue Diamond - 0.0400
Wizamet Super Iridium Extra Stainless - 0.0375
Gillette Sword - 0.0400
Gillette Platinum - 0.0375
Vidyut Super-Max - 0.0375
Gillette New Improved Stainless - 0.0375
Super Max Platinum - 0.0400
Trig Silver edge - 0.0375
ZorrikSuper Platinum - 0.0375
Croma Diamont Stainless - 0.0400

While he was measuring them all he was quite surprised they all measured so evenly across the board. Even measuring multiple samples of the same blades, all were the exact same thickness. There was no measurable variance between samples of the same stock, not only the same tuck.

DE blade tolerances are apparently, extremely tight.

I did ask about checking flex distance against pressure applied to the blade. While he doesnt have the equipment in his garage to measure that, but said it could be done, although perhaps, not by him lol.

Some blades are noticeably more flexible than others and although he has a metallurgical background he said because of the wide variance of coatings applied, composition, heat treating, etc, any comparison across brands would only be hypothetical.

The exact and likely entire process from base material to final finishing I would think to be kept under strict control and only with knowing and understanding the entire process and how each process is applied to a blade, and when, could give insight as to why one blade that actually measures thicker, appears to be more flexible.

So there they are, and not one tiny drop of blood lost by either of us. A miracle haha.

 

[Bhugo]

Very cool. Thanks for posting.

 

[ShavePastor]

Thanks Mike!

Interesting that GSB is 0.0350 and Nacet is 0.0450. Though GSB is the thinnest measurement (along with several others the same, but none any smaller than 0.0350) it still remains a top notch blade for me in any razor. It just works well. But I know for you, Mike, it's a terrible blade. ymmv is probably most true in the area of blades.

 

[psfred]

I think you dropped a decimal -- I believe nominal thickness is actually 0.004", not 0.040", or 0.10mm. 0.0395" is 1mm, and I'm quite certain a blade that thick would be very difficult to install properly in a Gillette DE.

I strongly advise against hand measuring "half thousandths" -- at that level, you are talking surface finish. Hand held micrometers have the divisions for half thousandths, but you can't repeat the readings unless you are in a climate controlled room using insulated gloves, the heat from your hand can "expand" the micrometer half a thousandth. Less likely with very thin material, but there is a reason micrometers have insulated grips. A little oil or a fleck of dust will throw off your measurement, too -- 0.0005" is a VERY small distance!

I suspect the thickness is related to the origin of the steel, although modern mills can do a really good job of making thin stock very accurately.

The original Gillette three hole blades were 0.006" as described in the patents. Probably a bit more variation in those than in modern ones. "Thin" blades circa 1932 were either 0.005" or 0.004", or both depending on maker. I have some very old blades that came with a German slant that are 0.004" thick, so it's not a modern thing. I've read somewhere that some were 0.005" too, but have not measured any.

Some makers are advertising 0.003" or 0.0035" blades (Dorco Trojan for instance), but I'd wonder about the ability to grind and polish a good shaving edge on something that thin.

 

[Esox]

@Cal has corrected and entered the information in my journal thread.

Mike @Esox’s DE blade thickness list in thickness/alpha order

in thickxxmm thickxxBLADE
0.00450” 0.114mm Gillette Nacet Stainless
0.00450” 0.114mm Shaverboy Super Stainless

0.00425” 0.108mm Gillette 7 O'Clock Super Stainless (0.089mm*)
0.00425” 0.108mm Lord Platinum

0.00410” 0.104mm Feather

0.00400” 0.102mm Astra Superior Stainless
0.00400” 0.102mm BIC Chrome Platinum
0.00400” 0.102mm Croma Diamant Stainless
0.00400” 0.102mm Derby Extra (pre 2016, current blade 0.089mm*)
0.00400” 0.102mm Gillette Sword
0.00400” 0.102mm Kai*
0.00400” 0.102mm Personna Med Prep
0.00400” 0.102mm Personna Platinum Chrome (Personna Red)
0.00400” 0.102mm Polsilver SI
0.00400” 0.102mm Rapira Platinum Lux
0.00400” 0.102mm Sharp Star
0.00400” 0.102mm Super Max Blue Diamond
0.00400” 0.102mm Super Max Platinum
0.00400” 0.102mm Voskhod

0.00390” 0.099mm Bolzano Superinox
0.00390” 0.099mm Shark Super Chrome
0.00390” 0.099mm Treet Platinum Super Stainless

0.00375” 0.095mm Gillette New Improved Stainless
0.00375” 0.095mm Gillette Platinum
0.00375” 0.095mm Gillette Rubie Platinum Plus
0.00375” 0.095mm Trig Silver Edge
0.00375” 0.095mm Vidyut Super-Max
0.00375” 0.095mm Wizamet Super Iridium Extra Stainless
0.00375” 0.095mm Zorrik Super Platinum

0.00350” 0.089mm Astra Superior Platinum
0.00350” 0.089mm Gillette 7 O’Clock Sharp Edge
0.00350” 0.089mm Gillette 7 O’Clock Super Platinum
0.00350” 0.089mm Gillette Silver Blue
0.00350” 0.089mm Perma Sharp Stainless
0.00350” 0.089mm Sputnik
0.00350” 0.089mm Treet Platinum
0.00350” 0.089mm Wizamet Super Iridium

* Information from “DE Razor Blade Dimensions Table” in the ShaveWiki.

 

[Dovo1695]

Awesome post! Fascinating that three PPI blades Nacet, Polsilver, and Perma-Sharp Super vary in thickness from the top end of the range to the bottom (.0045, .0040, and .0035 respectively). I guess that debunks the theory that they're all the same blade in different packaging ! They're all fantastic performers for me and I confess I'm not sure I could tell them apart in a blind shave test.

 

[Esox]

Awesome post!

Thanks, and thanks for the bump. I guess I should maybe post the amended information here too haha.

Nacet, Polsilver and Perma-Sharp Super I think I could tell apart. Nacet has that 'bare blade' feel to it for me. Polsilver feels very sharp at first use and Perma-Sharp feels a bit like Gillette Black to me, but without any harshness.

There are a few surprises. I would have sworn Feather blades were on the thinner side.

Thanks @Cal for compiling and setting the order.

in thick mm thick BLADE
0.00450” 0.114mm Gillette Nacet Stainless
0.00450” 0.114mm Shaverboy Super Stainless

0.00425” 0.108mm Gillette 7 O'Clock Super Stainless (0.089mm*)
0.00425” 0.108mm Lord Platinum

0.00410” 0.104mm Feather

0.00400” 0.102mm Astra Superior Stainless
0.00400” 0.102mm BIC Chrome Platinum
0.00400” 0.102mm Croma Diamant Stainless
0.00400” 0.102mm Derby Extra (pre 2016, current blade 0.089mm*)
0.00400” 0.102mm Gillette Sword
0.00400” 0.102mm Kai*
0.00400” 0.102mm Personna Med Prep
0.00400” 0.102mm Personna Platinum Chrome (Personna Red)
0.00400” 0.102mm Polsilver SI
0.00400” 0.102mm Rapira Platinum Lux
0.00400” 0.102mm Sharp Star
0.00400” 0.102mm Super Max Blue Diamond
0.00400” 0.102mm Super Max Platinum
0.00400” 0.102mm Voskhod

0.00390” 0.099mm Bolzano Superinox
0.00390” 0.099mm Shark Super Chrome
0.00390” 0.099mm Treet Platinum Super Stainless

0.00375” 0.095mm Gillette New Improved Stainless
0.00375” 0.095mm Gillette Platinum
0.00375” 0.095mm Gillette Rubie Platinum Plus
0.00375” 0.095mm Trig Silver Edge
0.00375” 0.095mm Vidyut Super-Max
0.00375” 0.095mm Wizamet Super Iridium Extra Stainless
0.00375” 0.095mm Zorrik Super Platinum

0.00350” 0.089mm Astra Superior Platinum
0.00350” 0.089mm Gillette 7 O’Clock Sharp Edge
0.00350” 0.089mm Gillette 7 O’Clock Super Platinum
0.00350” 0.089mm Gillette Silver Blue
0.00350” 0.089mm Perma Sharp Stainless
0.00350” 0.089mm Sputnik
0.00350” 0.089mm Treet Platinum
0.00350” 0.089mm Wizamet Super Iridium

* Information from “DE Razor Blade Dimensions Table” in the ShaveWiki.

 

[Dovo1695]

Better. Now it's a super-awesome post. It would be an interesting experiment to test the "flex load" of these blades. Place one end (length-wise) in a vice at a fixed point on each blade. Place a tiny little tray at a fixed point on the other end of the blade. Fill the tray slowly with sand until it bends 2mm as registered against a fixed ruler. Weight the sand on a high res pocket scale ($20 on amazon). Not volunteering, just a fun thought experiment.

 

[Esox]

Better. Now it's a super-awesome post. It would be an interesting experiment to test the "flex load" of these blades. Place one end (length-wise) in a vice at a fixed point on each blade. Place a tiny little tray at a fixed point on the other end of the blade. Fill the tray slowly with sand until it bends 2mm as registered against a fixed ruler. Weight the sand on a high res pocket scale ($20 on amazon). Not volunteering, just a fun thought experiment.

We did discuss that while we were measuring the blades and the friend that did the work said it could be done, but he doesnt have the proper equipment in his home garage.

A feeler gauge with a magnetic base will measure the distance of flex but I dont understand how he said he'd measure the force applied. I was to busy making sure I wasnt going to cut myself lol.

 

[Dovo1695]

I was to busy making sure I wasnt going to cut myself lol.

Good instincts. Amazing it you guys didn't spring any leaks during this experiment. Lord knows I would have!

 

[rasoio]

Thanks Mike!
So I've eventually found a common pattern across some of my preferred blades (7 o' clock yellow, GSB, Astra), they share the same reduced thickness
I'm wondering where the Silver Stars belong in the list, since I love them almost as much as the 7oc yellow..

 

[Roccomon]

Thanks, and thanks for the bump. I guess I should maybe post the amended information here too haha.

Nacet, Polsilver and Perma-Sharp Super I think I could tell apart. Nacet has that 'bare blade' feel to it for me. Polsilver feels very sharp at first use and Perma-Sharp feels a bit like Gillette Black to me, but without any harshness.

There are a few surprises. I would have sworn Feather blades were on the thinner side.

Thanks @Cal for compiling and setting the order.

in thick mm thick BLADE
0.00450” 0.114mm Gillette Nacet Stainless
0.00450” 0.114mm Shaverboy Super Stainless

0.00425” 0.108mm Gillette 7 O'Clock Super Stainless (0.089mm*)
0.00425” 0.108mm Lord Platinum

0.00410” 0.104mm Feather

0.00400” 0.102mm Astra Superior Stainless
0.00400” 0.102mm BIC Chrome Platinum
0.00400” 0.102mm Croma Diamant Stainless
0.00400” 0.102mm Derby Extra (pre 2016, current blade 0.089mm*)
0.00400” 0.102mm Gillette Sword
0.00400” 0.102mm Kai*
0.00400” 0.102mm Personna Med Prep
0.00400” 0.102mm Personna Platinum Chrome (Personna Red)
0.00400” 0.102mm Polsilver SI
0.00400” 0.102mm Rapira Platinum Lux
0.00400” 0.102mm Sharp Star
0.00400” 0.102mm Super Max Blue Diamond
0.00400” 0.102mm Super Max Platinum
0.00400” 0.102mm Voskhod

0.00390” 0.099mm Bolzano Superinox
0.00390” 0.099mm Shark Super Chrome
0.00390” 0.099mm Treet Platinum Super Stainless

0.00375” 0.095mm Gillette New Improved Stainless
0.00375” 0.095mm Gillette Platinum
0.00375” 0.095mm Gillette Rubie Platinum Plus
0.00375” 0.095mm Trig Silver Edge
0.00375” 0.095mm Vidyut Super-Max
0.00375” 0.095mm Wizamet Super Iridium Extra Stainless
0.00375” 0.095mm Zorrik Super Platinum

0.00350” 0.089mm Astra Superior Platinum
0.00350” 0.089mm Gillette 7 O’Clock Sharp Edge
0.00350” 0.089mm Gillette 7 O’Clock Super Platinum
0.00350” 0.089mm Gillette Silver Blue
0.00350” 0.089mm Perma Sharp Stainless
0.00350” 0.089mm Sputnik
0.00350” 0.089mm Treet Platinum
0.00350” 0.089mm Wizamet Super Iridium

* Information from “DE Razor Blade Dimensions Table” in the ShaveWiki.

As a retired QC manger for a local manufacturer, I can attest to the accuracy of Mitutoyo micrometers to .0005". Granted room temp and proficiency at using the equipment is always a variable, I think it is safe to say that the point of the study was to confirm the consistency of product. If the study was completed by the same person, same inspection area, same micrometer, same general time period, then the results should be considered accurate.

I say, good study, should leave no one doubting the precision of the manufacturing process. I also know that regardless of inspection process, sometimes that one defective product does sneak past even the best check points and inspectors.

 

[FoolishMortal]

Thanks for posting this! I'm not surprised that two of the thickest (7OC SS and Nacet) are my two favorite blades. More rigidity, less chatter, better results.

Vindication is mine!

 

[ShavingByTheNumbers]

Hey, Mike (@Esox). I checked your friend's single-sample measurements against my published data in the DE Razor Blade Dimensions Table. I was hoping that your friend's measurements would match with mine, but some do and some don't. The Astra SP, BIC Chrome Platinum, and pre-2016 Derby Extra measurements are within range of my published measurements for those blades, but the Gillette 7 O'Clock Super Stainless and Shark Super Chrome measurements are out of range of my measurements, greater than my measurements. Your friend's one Gillette 7 O'Clock Super Stainless measurement is especially circumspect because a thickness of 0.108 mm (0.00425 in.) is greater than anything that I've measured among many different blades. You'll have to take my word for it because only some of my data is published so far. I haven't published my Feather data, for example, because I've only measured four samples, but my thicknesses ranging from 0.100 mm to 0.101 mm with an average of 0.101 mm matches more closely to Feather's claim that their blades are 0.1 mm thick.

My measurements were done with a good ratcheting digital micrometer, zeroed out right before measurements and checked again right after measurements. Your friend's Mitutoyo micrometer is certainly more expensive with Mitutoyo having the best reputation, but measurement technique matters a lot, too. Was your friend judging when the measurement was done based on feel? Based on my personal experimentation with using feel, it is easy to end up with larger measurements compared to the true distances. Also, how did you guys ensure that the blades were fully clean of wax spots? I always make sure to carefully wipe off all wax with clean tissues and then use rubbing alcohol with clean paper to finish cleaning blades. That way, thickness measurements get right to the bare metal.

I realize that what I just wrote sounds like negative criticism. I didn't mean it to come across that way. What you and your friend did was cool. It bothers me that our measurements don't all match, and I'm hoping that the issues of feel and wax can help explain them away. Someone might suggest that stainless steel strip metal thickness could vary a lot for each blade, which alone could then explain our different measurements, but I've tried to eliminate that possibility with different tucks and purchases and I've never measured such huge thickness ranges for any blade. You and your friend didn't notice any thickness variation among multiple samples, which is close to reality since thickness ranges are usually relatively small. Treet Platinum is the blade with the largest thickness range that I've measured so far. The thickness ranged from 0.089 mm to 0.102 mm with an average of 0.097 mm among 50 blade samples, so the thickness varied from -8 % to +5 % relative to the average. Again, this is the largest variation that I've seen. Based on my measurements, blade thickness typically varies around +/- 2 %.

 

[Cal]

I'm wondering where the Silver Stars belong in the list, since I love them almost as much as the 7oc yellow..

I've just measured one for you rasoio.

Silver Star 0.004"/0.102mm

 

[AimlessWanderer]

Here are my thoughts as posted in Mike's journal:

A) From my understanding, and watching a "How it's made" clip posted somewhere here on the forum, the manufacturers do not carry out any thicknessing operations. The blade thickness is just stamped out, treated and sharpened, and finishes at pretty much the same thickness as that of the coil which was received from the steel mill.

B) The full deviation seen in this list is 0.001" from thickest to thinnest. How does that compare with generic mill tolerances for cold rolled product?

C) While we do not know the purchasing specifications of the various mills, generic tolerancing to international standards does exist. ISO 9445 covers thickness tolerances for cold rolled narrow strip.

D) Within this international standard, there are three different tolerance classifications; Normal, Fine and Precision.

E) While some enthusiasts may fixate upon precision, the fact of the matter is that a razor blade thickness isn't really a precision item, and there is no reason for the blade manufacturers to increase purchasing costs by requesting anything tighter than the Normal tolerance classification.

F) Normal thickness tolerancing under this standard, for a strip width of <125mm, and from 0.1mm thick, up to but not including 0.15mm, is +/-0.01mm. This means that coiled strip ordered at 0.1mm, can be anywhere between 0.11/0.09mm.

G) The vast majority of the blades measured fall within the ISO 9445 tolerancing band. Those that fall outside it do so by an exceptionally slim margin. This could be due to either further cold reduction from passing through the processing machinery, or face polishing to remove processing marks on the slimmer blades, or due to deposition of coatings on the thicker blades.

H) Due to the deviations all falling so closely in line with the international coil thickness standards, I would propose that all these blades are essentially made from the same specification strip - though not necessarily all from the same source. Furthermore, batch sampling taken from different mill runs (not blade manufacturing runs), may show deviations of each blade stock throughout this spectrum. Remember, when some people say blade X is thicker/thinner than blade Y, you are talking about them both being within one thousandth of an inch of each other, and both being within standard coiled strip thicknessing tolerances.

Further to this, when time permits, I hope to do some measurements of my own. The plan will be to set up a magnetic mount with a 0.0001" (one tenth) increment DTI, and the needle zeroed on a polished granite tile. Putting blades on the tile beneath the DTI will return very accurate readings and eliminate any potential error due to "feel". For those not used to handling micrometers, it's possible to incur errors due to feel of 0.0015", which is more than the total variation of the blade spectrum above. That is not to say that Mike's measurements are in any way inaccurate, just that the DTI method eliminates that potential.

I fully expect there to be some discrepancies between mine and Mike's measurements, not due to any error of measurement, but due to batch variations of raw materials. Some will no doubt be the same or similar, but I expect to see some blades sized up differently enough to back up the cold rolling tolerances as referred to above.

 

[rasoio]

I've just measured one for you rasoio.
View attachment 871200
Silver Star 0.004"/0.102mm

Thank you @Cal, much appreciated!
Now I'm left scratching my head... The silver Star is circa as good as a 7oc yellow in my piccolo, but their thickness turns out to be quite different.
So possibly thickness isn't the reason... Not in a fatip, anyway. Go figure..

 

[Roccomon]

Another consideration for thickness variation that may not be published anywhere, what tolerances are being used by the manufacturer? What both parties view as decrepancies in measurement techniques may be well within a started manufacturing tolerances. Does each manufacturer use identical tolerances? Without that tolerance info for each manufacturer, both studies can be considered sound as in both studies the representative samples from each manufacturer appear to be very consistent. Deviations will always exist, but generally due to different batch runs.

 

[AimlessWanderer]

Another consideration for thickness variation that may not be published anywhere, what tolerances are being used by the manufacturer? What both parties view as decrepancies in measurement techniques may be well within a started manufacturing tolerances. Does each manufacturer use identical tolerances? Without that tolerance info for each manufacturer, both studies can be considered sound as in both studies the representative samples from each manufacturer appear to be very consistent. Deviations will always exist, but generally due to different batch runs.

See Post #16

 

[ShavingByTheNumbers]

Another consideration for thickness variation that may not be published anywhere, what tolerances are being used by the manufacturer? What both parties view as decrepancies in measurement techniques may be well within a started manufacturing tolerances. Does each manufacturer use identical tolerances? Without that tolerance info for each manufacturer, both studies can be considered sound as in both studies the representative samples from each manufacturer appear to be very consistent. Deviations will always exist, but generally due to different batch runs.

Blade thickness varies because steel strip thickness isn't perfectly uniform. Based on my measurements of multiple samples of many different blades, blade thickness typically varies within +/- 2 % of average values. (Standard deviation is a fairer measure of variation, but it's easier to speak of range.)