Basically – a knife is just a hunk of metal that is thin on one side – the Apex – and thicker on the other – the Spine.
Primary Bevel refers to the angle from spine to apex.
On a chisel ground tool – the primary bevel “IS” the cutting bevel. These tools are fairly easy to sharpen as there is only one angle to deal with.
When there is a secondary bevel on a knife, things get a little more complicated. But not so for Professional Sharpeners or Cook & Chefs that know how to sharpen.
During use, your knife edge folds over, gets micro dents and nicks and just feels dull. This is normal.
In the diagram below, I show you the stages of a knife from “Sharpening” through normal use and then the need for Sharpening again.
Honing is the practice of using a strop or honing rod to realign the edge so that it is straight again.
In the photo below, the first picture is of a knife with a grind with bevels at 20 degrees per side (DPS) the overall angle is the Include Angle of 40 degrees (IA).
Check out my post on this subject: Degree per Side and Inclusive Angle Definition
This is where Chef KnifeWorks comes back into the picture. You will need to remove material and re-establish the secondary bevel again.
NOW – here’s the number question we get when customers pick up their knives from us – How long will my knives stay sharp and when should I come back???
It’s a two-parter, I know. The only answer I can give is a guideline based on a guess.
If you cut everyday on Bamboo – 3 months.
Use your knife only during Christmas? See you next year.
Plastic cutting board for about 30 minutes a day – you’ve got six months.
It’s all about performance – if you notice the knife getting dull and you hone or strop properly, then that’s when to give us a call.