Thread: Filarmonica Sub Cero

I am actually a bit unclear on this because a blade can be fully hollowed out without being bi-concave, but maybe that would not be a stable configuration and would create too much flex if it reached the delicacy of a biconcave.
When you look at a single concave blade from the front, it just has a single smooth curve from the spine to the edge. A binconcave grind has one concave surface going from the spine to 1/2-2/3 of the way down, then a little belly appears and from that belly there is a smaller concave curve going down to the edge. A quick and easy way to know is to look at a blade with the toe facing toward you and to see if it's a smooth curve or it has that belly.

Here's some interesting info coming from Arthur E. Boon:

http://www.en.nassrasur.com/razorcentral/grind.html
This will give you an idea of the belly that I was talking about.

http://www.en.nassrasur.com/razorcentral/identify.html
And this is a quick and dirty way to identify without looking for a miniscule belly.

Read the whole document, it's very informative. I still read it for entertainment purposes.

What Razor Central doesn't show is what would be referred to as 0/4 (simple hollow ground) if we wanted to be consistent. That is a single concave from spine to edge. This really shouldn't be called a wedge, because a real wedge has flat sides, as Boon shows.

Thanks Joe. That was one instance I was iffy about when it comes to nomenclature.