AvidCNC RapidChange ATC tool pickup and drop off test2 - Go bigger or go homer 

Yes the magazine employs patented geometry to hold the nut in place. @JNWoodworks has a good video exposing the inside

If you have a look at some of RapidChange's development videos you'll see that the nut-holding/grasping part of the magazine was the breakthrough that made the system work reliably. It's not a hexagon - it's a spring-mounted ball bearing arrangement.

Cross Threading: ACTUALLY cross threading the hardened steel of the spindle would require EXTREME torque, far beyond the 14 foot pounds that our system delivers. The only potential problem is for the nut to become stuck at the start of the threading process. The ONLY way this could possibly happen would be through GROSS MISALIGNMENT where the spindle shaft is NOT perpendicular to the magazine. After thousands of tool changes I have found that the only time it fails is when I force it to. The precision and repeatability of CNC and the RapidChange ATC Magazine, inherently prevent this from occurring! Manual tool changes are a hassle for many reasons, mainly because it’s difficult to start the threading process by hand. Precisely holding the nut relative to the spindle shaft is not that easy when you're trying to do it quickly. We just end up fumbling around until they line up and we can finally thread the nut. Then we grab our wrenches and finish tightening it. This brought to mind the fear of cross threading when I tested the first prototype and I will admit, it was a tense moment. I was almost waiting for it to happen, when suddenly it smoothly loaded the tool and I jumped for joy. Then it became obvious as I remembered that a CNC is a precision machine. It will return to the same location in X Y and Z and in the same orientation vertically every single time without fail. This is why we use computer numerical controls on machines in the first place. When the clamping nut is in the same location and orientation every single time, why wouldn't the nut thread perfectly? The RapidChange ATC Magazine holds the clamping nut precisely in the same location and orientation after being unloaded every time due to the design of our RapidChange Socket (which by the way is NOT a hexagon, this geometry does not work when unloading the tool). Every time a tool is loaded, if the spindle and nut are always precisely aligned and oriented, this makes it far more repeatable and accurate than changing tools by hand, not to mention much faster.

It won't cross thread - see info below. And as the magazine and parts are mostly plastics of various forms, if anything goes wrong the mag will be destroyed long before the spindle goes. I've crashed ½ inch carbide bits through 20mm aluminium bench dogs which is much more force than would ever go through the ATC if something went wrong. The spindle still lives!