螺母与螺栓

A metal bolt with a nut threaded around it, as by a wrench. Often positioned at a 45° angle, the head of the bolt at the upper left. Commonly used for various content concerning tools, building, and construction. May also be used for other hardware, including screws.

Apple’s bolt previously resembled a screw, Google’s a dumbbell; Microsoft’s design previously featured the nut and bolt separately.