Originally Posted by mturnerb
Physics alone would suggest that any perceived superiority of one device over another is erroneous. The die will do what it is designed to do if the proper force is applied to properly prepared material - velocity is the only difference in techniques and count me "dubious" as to whether that has anything to do with it.
I did a rough estimation of a #8 screw dimple with a 2lb hammer and a 5 lb hammer. I ignored the mass of the set holder since it's (sort of) 0 due to the spring. I also ignored the flat area of the die since it has almost no effect on the dimple. I used the area of the dimple itself (0.340" diam; 0.050" depth)
Swinging the hammer at 5 m/s (which is a pretty good whack but very doable), you get ~2400 psi out of the 2 lb and ~6000 psi out of the 5 lb. #40 and #30 will be even higher.
Your average pneumatic squeezer is rated for 3000 psi. I don't know what the drdt2 is rated at, maybe half that?
That said, I tested the c-frame vs my pneumatic with a 1-1/2" yoke when dimpling the tank and couldn't tell the difference. And i've used the c-frame, a 3000 psi pneumatic, a 6000 psi pneumatic (gator jaws) to dimple #30 and #40 and they all look exactly the same to me.