Quote Originally Posted by Patrick Baney View Post
I have two narex mortise chisels and their parallelogram geometry makes it impossible to chop a rectangular mortise. They're visibly out. Some may be ok with this, but I am not.
This is why I favor English mortise chisels (“pigstickers”) over sash mortise chisels. Besides being beefier, they are designed with a trapezoidal shape so machinist-level tolerances are unnecessary.