Of Safety Razors and Blades - Aggressive or Mild, Sharp or Smooth - A General Overview

A lot of discussion has gone on in various threads and posting about why razor and blade combinations seem to work differently for different individuals. Now the first two and in my view most important components of shaving concern the skin/beard type and the technique that has been mastered by the shaver. The dermatological and technique points are very large areas to discuss and is not the focus of this discourse which is Safety Razors and Blades.


Here are some of the issues that affect what is called aggressiveness or mildness of a razor.

1. Blade Gap - The gap between the cap (doors for TTO) and the base plate, or space from the head top and base in case of SEs and Injector razors. This allows space for the hair to protrude in front of the cutting edge in order to be cut. A larger gap allows more skin/hair to come into contact with the cutting edge of the blade. Different gap sizes allow one method of increasing or decreasing the amount of blade exposure to the skin. That gap is the element of adjustment on most "adjustable" DE razors.

2. Head Curvature - This is the curve of the head. That is the pivot that allows you to create the blade angle of approach (or flatness in terms of SEs and Injectors).

3. Blade Guard. This guarding apparatus is what supposedly makes a razor a "safety razor." This is often referred as the Comb or Guard Bar types by many users. If the blade guard has teeth that have open spaces (open gaps) that is an Open Comb. If it has ridges (teeth that are not gapped) that is considered to be a Closed Comb. If the gaps in the teeth seem to be more of a web shape (which are not quite totally gapped or closed) it is generally called a Hybrid Comb. Razors that have guards that are a straight bar providing space between the razor and the skin are called Guard Bar razors. There can be more variations but these are ones that are most commonly referred to. The type of guard can be used in combination with the blade gap to either accentuate or reduce the level of exposure to the skin.

4. Weight of Head and size matching of head to plate. How much the head and weighs (cap/doors and base plate combined for DEs) can quickly change the center of gravity of a razor which will be discussed below. Size matching is where the size (width) of the cap/doors is changed relative to the size base plate. This can be used to increase or decrease blade exposure to the skin as well as gaps and guard types. Size matching can also be seen on various SE and Injector variants (top versus plate) to allow more or less blade exposure.

5. Handle Length - How long the handle is. That acts as a lever. The longer the handle, the more precision angle you can make since it take more motion to create angle changes at the head. A short handle will react with a greater angle change because it takes less physical difference to move the head at an angle.

6. Center of Gravity - This is where the entire razor (head and handle) if held on a single point would balance. If the center of gravity moves forward toward the head, it can apply more pressure so that is important. A hollow handle and a solid handle will cause two razors of the same size with the same head and materials to have different centers of gravity.

7. Material types can also affect the aggressiveness of a razor. Heavier metal razors will react differently than lighter plastic razors of the same design and dimensions.

There are more areas beyond this that I have not listed. This seems like a large amount of information to digest, but the design of mechanical items is not always straight forward. That is why there were so many different variant designs just on the double edge razor alone from the 1900s until now. Throw in SEs and Injectors and the lists gets much longer. Hundreds and hundreds of small tweaks to larger variations to the various designs are documented pictorially in various books and articles on this subject that provide greater detail than what can be afforded here.


Now that we have discussed razors, there is more to a blade than simply sharpness that affects a shave.

1. The consistency of the edge is critical to the smoothness of a blade. You can have honing that produces the sharpest edge in the world that could cut a hair easily but if it is an irregular edge, caused by inconsistent stropping, and that sharpness will be your worse nightmare. Smoothness is accomplished by the accuracy and consistency of stropping pattern produced at the factory and the composition of the blade material as well. The balance of sharpness and smoothness is a serious issue when choosing a blade.

2. The hardness of the edge is what provides longevity to the blade, but also reduces absolute sharpness (life cycle versus absolute sharpness). You can have sharpness without smoothness which leads to irritated and skin nicks and cuts. You can have smoothness with limited sharpness which leads to a blade that last only a couple of shaves.

3. Various blade alloys also contribute to the blades life and handling. Generally carbon steel blades will provide a nice smooth shave for maybe the first couple of shaves and then will quickly dull and rust. Stainless steel blades, using mixtures of metals nickel, magnesium, chromium, tungsten, titanium, etc. to produce various alloys, allow for a harder stronger steel to be produced that is much more resistant to rusting. The harder steel allows an edge to be retained longer than carbon steel.

4. Coatings or lack of coatings also contribute to the blades life and handling. Coatings can serve two purposes, to provide and even harder edge to the blade, or to reduce friction while shaving. Some blades use stainless steel and then a coating of nickel, chromium, tungsten, titanium, ceramics, etc. are applied to increase supposedly increase smoothness and strength at the edge of the blade. Coatings such as Silicone, Ceramics, and PTFE (Polytetrafluoroethylene or Teflon DuPont Trade Mark name for PTFE) are used to reduce friction between the blade and the skin to allow the edge to move more freely during the hair cutting process. Please note that some individuals have skin sensitivities to various coatings and metals so that will also need to be taken in account by some when finding the right blade. Blade samplers are recommended for these reasons.

Lastly what can be some of the impacts of just one razor and a variety of blades can be seen on a study I did for myself some time ago which shows the variations and why it is important to find the right blade and razor for more successful shaves.

http://theshaveden.com/forums/threads/de-blade-challenge-ii.28223/

The following two links are contained within the link above. This provides quicker access.

https://sites.google.com/site/gdcarrington1/home/de-blade-challenge-ii

https://sites.google.com/site/gdcarrington1/home/de-blade-challenge-ii-addendum

The ideal strike is to have a sharp enough blade with a hard enough edge to last at least 3 to 5 shaves with a very consistent stropping pattern to allow you the smoothness to enjoy the shave.

Aggressive / Mild is the description for razors.

Sharp / Smooth is the description for blades.


Even though this is not an exhaustive view of these two topics, I hope this thread provides helpful information to the Traditional Shaver using Safety Razors and Blades.

Thanks for viewing this article.

 

Great write-up.

If my memory has not gone completely blank, but you have posted this before, correct?

I believe I remember poring over it at length while researching wet shaving.....

 

Thanks and you are correct. Parts and pieces of this are in different places but not in a central location. This overview provides some more meat to the discussion as well.

 

Great idea to further centralize it. It was extremely helpful in many of the initial decisions I made....

 

Thanks and I am glad that the "bits and pieces" helped you along the way.

 

Excellent article, Gary. Thanks.

Now maybe folks will stop addressing blades as "aggressive" and apply the term to razors, as it should be!

(yeah, that's a peeve of mine )

 

Thanks for the write up..the article has you're usual comprehensive style..
Though consideration of these many factors might be truly helpful in blade selection, I will probably still stubbornly end up with the tried and true, try it you'll like it approach..less scientific, but I'm kinda set in my ways lol...

 

Thanks! This helps a lot for this noob.

 

So where can I find blades that are aggressive? I like aggressive blades.











Thanks for putting this together, Gary!
An excellent resource of good practical info!

 

If some company comes out with a line of blades called AGGRESSIVE!, it would cause some confusion amongst the ranks!

I appreciate the kind words from all of you.

 

Gary
This is an excellent write up and review. Thanks for taking the time to post it.

 

My question is "How Can a Blade be aggressive" isn't how you pull the razor across you face and or be caused by how hard or how much pressure to apply to it and your face?

 

Then there is fault with technique, not the blade.

 

That is Steve's point exactly and mine as well. A blade cannot be aggressive or mild. That is the properties of the razor. We constantly have to remind the users (Blades = Sharp, Smooth, Dull) and (Razors =Aggressive or Mild with various modifying words to describe the ranges in between the extremes.)

Technique is a fault concerning blade and razor. Mismatch to skin type (using items that cannot be as efficient, or as mild to the skin) can cause major issues as well but that is another long discussion.

 

To all who have read this I hope it provides solid information you can use in the future. Thanks!

 

The old Face Guard blades sure looked aggressive, like they had teeth. Aggressive, they were not. At all. I think I still have one laying around...maybe just for old time's sake...nah.

 

Gary
Why would the information not be useful.....The Shave Den has a treasure trove of useful information and maybe some useless information too.
There is no such thing as a stupid or useless question.

 

Steve, this one made me smile when I read it.

http://theshaveden.com/forums/threads/which-do-you-choose-the-hard-or-soft-option.37897/#post-670588

 

Thanks for the write-up. I'm new and all the great info helps.

 

Once again I have gained knowledge and more understanding from your posts,however still looking for the reason why every time I use a fresh blade my neck more like a " bloodletting " compared to the rest of the shaves with the same blade?doesn't matter on the brand any advice?