This is strange, I thought I had responded to this threqad and sent a PM But not showing on the shop computer,
Any way the reason the screw stick up about .019 of an inch is the square inserts are .019 thicker that the r-18 You aren't going to break an insert since the force is generated against the 82 degree bevel of the screw and insert, We've done a few hundred of the tools, and no one has broken an insert yet fro tightening it down, (Not to say some one could get their pet Gorilla to try) but I think they would either strip the hex hole from the screw or strip the hex wrench, I think a lot of bolts and threaded things get broken by folks trying to over tighten them. I'm not sure what the shear point is in Torque, but I think you would first strip the screw.
For one thing there is no reason to tighten the screw much beyond what is required to hold the insert from twisting, every time you over tighten any threaded device, even Stainless you are stretching the threads, we drill and tap for 80% thread depth which is better than the nuts and bolts you'll get at the local Box stores. If you have a Micrometer, or even a set of Dial indicators measure the thickness of the square, r-4, r2 Inserts and r-18 and you will see why the top of the screw sits above the insert. If you have any problem please don't hesitate to phone me, Chances are I can answer your question. If you'll notice the picture on the website it shows the screw above the insert, We could have cut the top thinner, but that would lead to stripped screws and just dumb nasty stuff.
I'm not trying to sell any thing Mods, just trying to help with a problem the man has with a tool, I've sent him a PM and tried to help, I thought I was working within the posting rules
Ken