Many times how it looks has little to do with what is actually set at the angle for pitch. You can easily find two examples of the same model knife even made in the same month of the same year that each have a different look to how sharply angled it is but yet both are the same setting. How this is done can be any number of ways it was trimmed out or cut out with modern machinery and techno gadgets. From the perspective of doing this with a grinder by hand the old fashioned way it can go something like this very easily. How high or low the table is set in relation to the wheel used to make the grind pitch angle contact on your blade can play in how it comes out.
For example, if you use a 10" wheel to grind the contact angle you can have your table angle set at 8 degrees. If you had three separate blades and set the table height for the first blade so it was sitting dead in the middle of the axis of the pivot on the 10" grinding wheel you would see one grind. If you then lowered the table by a tiny bit so it set slightly below the axis pivot of the wheel, all the while leaving the table tilt at the same 8 degrees you would then have a different grind and yet your table is still set at the same 8 degrees. If you then raised the table to above the axis pivot of the big wheel you use it at that height you'd get yet a different angle all the while the table is still set at the same pitch angle of 8 degrees. In contrast how high or low the table sits on a flat platten is not going to affect it at all.
If you are speaking of the contact on the blade itself there are different schools of thought as to what angle is best. Some makers use 7 degrees concave. Some prefer 7 degree flat. Some like 8 degrees flat, others concave while others like 10 degrees for frame locks 7 degrees for liner locks and so on. We could debate all day as to which type of contact (flat or concave) is best. Even the companies have changed how they did them just a few years back to how they do them today in this regard. Then again we could debate as well as how little or how much of the actual lock comes into contact with the blade for actual 'foot print' of physical contact, how much should be taken out of the thickness for the lock slab to bend the lock in the back to put the spring tension in the lock, which side the relief cuts should be on, outside or inside, how long the long and short cuts should be to mill the locks and on and on. In the end all that matters is that its a quality product that the maker backs because he himself, or herself does what they do after deciding its what they feel is best for any number of reasons. Many times its what they feel they can duplicate to the highest consistency over and over again.
There is a fine line between how well a lock wears or how long it takes to cross the tang vs how reliable it is to trust in use. If the angle of contact is too sharp the lock can defeat much easier with far less spine pressure on the blade or from far less sudden shock causing the blade to snap shut cutting whatever is in its path on the way, IE, your fingers! Not good! If I had to pick between a lock I could trust my fingers with, even if it meant it may wear a little faster vs one that wears a long time but can't be trusted to even secure the blade I'll take the one I can trust that wears a bit faster each time every time personally.
STR
