What's the advantage of a secondary bevel on gardening shears?

jpollard

Anyone an expert in garden tool sharpening?I'm sharpening a pair of gardening shears. They seem to only have a single, wide, shallow bevel on both blades. Most shears I see have a much narrower secondary bevel. I'm wondering whether it's worth putting a secondary bevel on them or whether to stick with the manufacturer's setup?

pansyface

In the days when I was a bookbinder, I used to sharpen my knives with a double bevel.

The first, shallow, one was really just to reduce the thickness of the blade from the thickness of the body of the blade down to the cutting edge. The second bevel, being steeper, served two purposes.

Firstly, the steeper angle gave greater “bite” when applied to the leather.

Secondly, it served as a means of removing the tiny bits of metal, the “swarf”, that were still stuck to the blade after the sharpening process and so made the cut “cleaner”.

Similarly, scissor blades are “hollow ground” or slightly concave on the cutting sides to make for less friction and a cleaner cut.