Hindson Tower Bolt with Stainless Steel Rod and Stainless Steel knob for Door, Window, gate (Aluminum Body (chatakni) 4 inch Use on vertical, horizontal, left- or right-hand applications, in vertical use, the notch-in case holds the bolt in a locked position. Deadbolts are door latches that can only extend or retract by turning the knob or a key. It does not have a spring to keep the bolt extended. Thus, it does not automatically latch when the door is closed