Derby numbers

[bmyers448]

In changing out my Derby blade the other day, I noticed numbers on both sides of the blade. Each blade edge is numbered. 1 and 2 on one side. 3 and 4 on the other. This is obviously to identify each edge. But I'm curious as to why? Does anyone use one side of a blade (edges 1-2) and then flip the blade (edges 3-4) before changing to a new blade????

 

[Toothpick]

As far as I know, based on knowledge gained here, the numbers on blades serve no purpose outside of the factory. They are used in quality control.

What you suggest could be a great way to use the numbers though. I twist my razor during the shave to use both sides so wouldn't work for me.

Or maybe after each shave use a marker to cross out a number.

 

[swinub]

It seems most everyone twists the razor every few strokes to use each side evenly. I've heard some people say that they also clean their razor and flip the blade over between shaves, so I guess the numbers would help there. In theory that should result in the most even usage of the blade, which could (maybe) make it last a little longer.

 

[bmyers448]

That's what I'm thinking too. Start with edges 1 and 2 for a few shaves. Flip it for the rest of your shaves before changing it. If you open your razor and it's on edges 3 and 4, you know you've already done your flip and it's time for a new blade .... on the side with edges 1 and 2 to start.

Im just wondering if a blade needs changing whether you get any more life out of the edges by flipping them over and shaving from the other side? This is the only reason I can see paying attention to these edge numbers......to keep track of flipping.