by nine4t4 » 9 Aug 2016 15:29
Don't get hung up too much on labels. I don't have SouthOrds but I'd guess that the right most is the standard and the left-most is shallow. I wouldn't worry about it. With practice, you'll know. the ones in the middle look a bit extreme if you're working with standard locks.
What works for one lock may not work for another. The deeper hook may work better up to a point, but then it leaves you less room to move around pins that are set and cut deep. The shallow hook, may move easily between pins, but you strike other pins with the shaft if you don't angle enough. Or you're working on a slightly smaller keyway like some padlocks, where the extra depth isn't necessary.
If you have the keys for the locks you're working on, compare the range of cut depths to the depth of the hook. The hook that is closer to that range is your starting point.
Have fun with them