From ShaveWiki
Double edge blades are standardised and measure 1-11/16" x 13/16" / 43 x 21 mm. They are usually made of stainless steel, but carbon steel blades also exist. Many blades have coatings (for instance Feather make platinum coated blades). Double edged blades usually come in cardboard or plastic boxes with five or ten blades per box. In addition to this, most brands have each blade individually wrapped in paper.
History of Double Edge Blades
The DE blades that you can buy today are different from what you could buy a hundred years ago. The original DE blades used by Gillette were almost rectangular, with slightly rounded ends, and only had three holes. They were also noticeably thicker than the current DE blades.
The original model stayed as it was for about 25 years. It was not until 1929, when a series of changes were made. It was in this year that King Gillette's patent expired, opening up the market to a host of competitors, all with their own twist on the standard blade. One important change to users of old razors (before the Gillette New Improved) was that the blades became thinner. Shavers who wanted to use the older DE models could compensate for the difference in thickness by adding a shim, such as a small paper clip, between the blade and the blade guard when putting a blade in the razor.
After four redesigns, in 1933, the razor blade as we know it was launched and has (at least in shape) stayed the same. Since then, other improvements have been made, such as in the materials, to make sharper and more durable blades.
History of Single Edge Blades
Other Blade Types and Shapes
In addition to the normal straight edged SE and DE blades, there have been various other shapes. A number of rounded models have existed with matching razors. These were usually not for facial hair, but for shaving armpits and other areas.
See Also
List of Razor Blades - A comprehensive list of razor blades, organized by manufacturer.
Category:Brands of Razor Blades - Listing of the manufacturers who make razor blades and have their own page on the B&B ShaveWiki.
External Links
The evolution of the double edged blade
