If you hold a T20 bit next to a TX20 bit, the difference becomes obvious immediately.
: A T20 driver bit will fit perfectly into a TX20 screw head and vice versa, as they share the same geometry. Common Usage :
: Six-pointed star (hexalobular internal) designed to prevent "cam-out" (the driver slipping out under high torque).
: Both have a point-to-point dimension of approximately 3.84 mm .