Sentence:  Because the pressure is a steady, controlled flow, the available tonnage of a hydraulic press brake is the same at all points during the downstroke (Figure 1C-9). The ram can also be instantly stopped, anywhere during the <WSD>downstrike</WSD>, by simply releasing the foot pedal. 
Meaning of the word marked with <WSD> tags:  A downstroke; A downward movement that terminates in striking something.