Stroke length (also known as the machine’s “throw”) refers to the distance the needle
moves in and out of the machine in one rotation. Machine stroke affects how hard the machine hits, as a
longer stroke allows the needle to build up more momentum, and also how fast the needle moves. Stroke length
has an effect on your maximum needle depth, but isn’t necessarily connected. Most rotary tattoo machines
come with a fixed stroke length, but in some models it can be adjusted.