Well, I just couldn't find a digger that would 1) dig deeper 2) hold its cutting edge and 3) stand up to serious prying.
Fortunately, I'm a knifemaker and can do something about it. I came up with this design a few years ago and its been faithfully performing ever since.
I used 5160 steel and heat treated it to bainite (which is special way of imparting extreme toughness on a few select steels that respond to the process) and then hardened only the outside 3/8" of the edge. So, the edge remains very sharp, and in fact, self sharpens when thrust into the dirt. The digger is 2" wide at the widest point, and then tapers towards the tip. This design works well for me as I like to keep holes as small as possible, and generally cut a deep "trap door" in the sod (5" to 6" deep and 5 to 6 inches per side), then pry it up. This baby is for all intents and purposes, unbreakable...and I've tried hard to do so! Its 1/4" thick at the shaft, and the trowel end is slightly hollow ground on one side, and double hollow ground along the edge on the back, and has a taper that makes it easy to slice into the soil. But where it shines is prying up the dirt/sod in just about any condition. I made it as long as it is because I am still optimistic about finding very deep coins with my SE...just haven't walked over very many.
I thought about marketing it, but found out it would be too expensive to be competitive, so I just make them for friends at cost when I have some extra time. Actually, I was thinking of sending one to Bryce for his opinion, so Bryce...if I ask for your address, it won't be for any nefarious reasons!
Knipper