
These chisels are good for what they are and great value for money. I haven't noticed any significant concavity/convexity on the back of two chisels I've had over the past few years (1" and 3/4"). They seem to need very regular sharpening, but it's easy to get a good edge in no time (probably, one reviewer suggested, given the comparative softness). Very good weight and comfortable working over a long period of time. Don't hit them with a metal hammer and then expect them to be handy for manual cleaning as I've found the plastic warp a bit. I guess that's why I'm buying a new 4 piece set.