I recently tore apart a Rockwell Bladerunner RK7320 because the factory blades (T-slot) kept flying out almost impacting my eye, and the blade twists whenever the locking mechanism is held on the blade. To my complete surprise, the slot inside the machine is 0.1mm wide exactly, and the blades I have are on average 0.0425mm wide. Ranging from a minimum of 0.039mm to a max of 0.058mm. The bearings at the top that support the blade is about the same distance wide, 0.1mm.
I've scoured across the internet, and to various hardware stores, to come to the conclusion that the machine I have, was fitted with the wrong sized slotted rod, because the blades are almost all the same range in thickness. If I had another RK7320 saw to compare, I can say that the company made a gigantic error, if I had another different jigsaw, I'd say there is probably a reason why the slot is way bigger than the blades.
If anyone has an answer for why this is, please let me know. If not, I will be cutting some T slots off other blades to epoxy to the blades I have so they can fit down in the slot that it was made for, and they don't fly out of the machine, or twist.