Know your blade gap

If you shave with a double-edged or single-edged safety razor, you may know about blade gaps and their relationship to how aggressively a razor shaves. But most of you do not know the actual gap of your razor (or razors). There is no good reason to know how wide of a gap there is between your razor blade and the razor’s safety bar if you are happy with your shave. How wide of a gap between the blade and the razor is just one factor contributing to aggressiveness. The best measure is how your razor feels to you.

However, I can think of two good reasons to know your blade gap. The first is if you are a beginner and your current razor isn’t giving you as good a shave as you hoped for, the gap is a starting place to discover a razor that works better for you. Perhaps you feel as if your razor isn’t doing anything because it takes more than three passes to get your beard taken down to smooth skin. You need a more aggressive razor. The opposite situation is if you really hoped to like wet shaving with a safety razor, but no matter what you do, your skin is irritated, and you end up with nicks and cuts. Try a less aggressive razor.

You need to know where your razor is to know where to go next, and the razor gap is one easy measure to help you identify the razors you want.

The second reason is one that pertains mostly to me. I am a retired scientist. I am curious. Measuring things and analyzing the data is, for me, fun.

I measured the gap on the three razors I own. A Merkur 34C measured 0.020 inches. My Leaf Twig single-edged razor (which uses half of a double-edged blade) measured 0.019 inches. Finally, the Vikings Blade Chieftain JR measured 0.024 inches. The measurements correspond to my impression of the feel of each razor. The 34C and the Twig feel very similar and mild. The Chieftain JR felt more aggressive but not too much so.

Blade gap is distance between blade and razor.

I am not the only one who has measured the blade gaps of razors. You can find the information online at several sources. Unfortunately, not every razor has been measured. Also, some of the numbers do not agree with others. This could be an experimental error in the measurements, poor measurement technique, or a real difference because of the age of the razor, even a difference between batches due to minor design changes. However, most of these differences are small and wouldn’t impact any decision you made regarding a comparison between razors.

The Merkur 34C is on all the lists because it is popular. My measurement agrees with what others reported, which gives me confidence that the measurements I made for the Twig and the Chieftain JR are accurate.

A feeler gauge is used to measure the gap between blade and razor.

If you switch to an adjustable razor, knowing how your non-adjustable razor’s gap compares to the gap at the different settings on the adjustable will suggest where to start, although, again, just shaving until you find a setting that feels right is the best guide to adjusting your razor.

Gap measurements of Safety Razors

Blade Gap Size inches	Razor & Setting
0.008	Rockwell Razor R1
0.010	Above the Tie M1 & M2
0.011	Standard Fatboy Setting 1
0.012	Rex Ambassador Setting 1
0.014	Rockwell Razor R2, Aristocrat Slim Setting 1
0.015	Merkur Progress Setting 1, Standard Fatboy Setting 2, Standard Slim Setting 1
0.016	Aristocrat Slim Setting 2
0.017	Standard Fatboy Setting 3, Standard Slim Setting 2
0.018	Muhle R89
0.019	Rockwell Razor R3, Timor, Standard Fatboy Setting 4, Leaf Twig
0.020	Merkur 34C, Executive Shaving Co. Mild Outlaw, Aristocrat Slim Setting 3
0.022	Merkur 20C, Merkur Progress Setting 2, Standard Slim Setting 3
0.023	Above the Tie R1 & R2
0.024	Above the Tie S1 & S2, Rockwell Razor R4, Vikings Blade Chieftain JR
0.025	Gillette Flare Tip, Rex Ambassador Setting 3, Rex Envoy, Aristocrat Slim Setting 4, Standard Fatboy Setting 5, Standard Slim Setting 4
0.026	Aristocrat Slim Setting 5
0.027	Rockwell Razor R5, Standard Slim Setting 5
0.028	Merkur Progress Setting 3, Executive Shaving Co. Braveheart
0.028	Executive Shaving Co. Outlaw
0.029	Muhle Rocca
0.030	Standard Fatboy Setting 6, Standard Slim Setting 6
0.031	Rockwell Razor R6, Aristocrat Slim Setting 6
0.033	Merkur Progress Setting 4, Aristocrat Slim Setting 7, Standard Fatboy Setting 7
0.034	Standard Slim Setting 7
0.035	Aristocrat Slim Setting 8, Standard Fatboy Setting 8
0.036	Above the Tie H1 & H2, Standard Slim Setting 8
0.037	Merkur Progress Setting 5, Standard Fatboy Setting 9
0.039	Aristocrat Slim Setting 9, Standard Slim Setting 9
0.051	Rex Ambassador Setting 6

Measurements for the above table are combined from the first two sources below, plus the measurements I made.

The table at Badger & Blade has gaps that do not agree with the other two sources. I don’t know which numbers are correct if either. The first two references are close but do not agree with each other for all the measurements.