Which Gap Numbers Are Accurate?

[REV579]

I have found 2 different sources identifying blade gap specs for Gillette Adjustables. In this case, referencing Fat Boys.
The first reference I found and documented(without notation but I believe I found it here) stated the following gap spacing:
1-0.56mm
2-0.61mm
3-0.66mm
4-0.74mm
5-0.81mm
6-0.89mm
7-0.97mm
8-1.04mm
9-1.14mm

This evening I stumbled upon a site that state the following gap specs:
These figures are converted from inches to MM
1-0.279mm(0.011in)
2-0.381mm(0.015in)
3-0.431mm(0.017in)
4-0.482mm(0.019in)
5-0.635mm(0.025in)
6-0.762mm(0.030in)
7-0.838mm(0.033in)
8-0.889mm(0.035in)
9-0.940mm(0.037in)

 

[cyberdog]

Depends on the model, they differ. See the chart below.

 

[rudyt]

The first set of numbers look like they're from the B&B Wiki and are the accepted standards. Your second source from G.Conti shows much tighter gaps, but that may be because he measures gaps differently.

If you're measuring the gap with a feeler gauges inserted narrow end first and very shallow, then use the first set of measurements.

 

[Dovo1695]

From what I've been reading, the blade gap isn't as important as the blade exposure and guard span. Comparing two razors by comparing their blade gaps is like trying to compare their "aggressiveness" based on the number of consonants in the model name. It might be correlated, but it's not the primary determinant. Guard span is easy to measure, so there is a lot of documentation about it; the other two are harder to measure (blade exposure & guard span), so there isn't nearly as much published data.

@ShavingByTheNumbers has some great info on this that's worthwhile reading.

Edit: In fairness, blade gap and guard span are often correlated, but this is not always the case; guard span/blade exposure are the primary determinants.

 

[romsitsa]

The thread of the dial has a constant elevation and the settings are spaced equally on the ring so the distances between the different settings should be the same. Like a constant increase by 0.05 mm from 1-9.
But all charts show incoherent distances. Why?

Adam

 

[cyberdog]

Here's some additional info, supposedly from an internal Gillette memo on exposure.

 

[cyberdog]

Here's an add for their first adjustable, which looks like a New Improved to me, but not positive. - isn't this just not fully tightening the knob?

 

[REV579]

The thread of the dial has a constant elevation and the settings are spaced equally on the ring so the distances between the different settings should be the same. Like a constant increase by 0.05 mm from 1-9.
But all charts show incoherent distances. Why?

Adam

I did wonder about that, yet this is an assumption on our part. I also recognize the distance/variance is measured micrometers.

 

[Blueskye09]

Never would have guessed a fatboy had this much blade gap based on the shave , they feel very mild even on 9.