A ratchet 
is a mechanical gadget that allows continuous linear or rotary motion in mere one direction while stopping motion in the Ratchets Wheel opposite direction. Ratchets are trusted in machinery and equipment. A rachet consists of a round gear or a linear rack with the teeth, and a pivoting, spring-loaded finger called a pawl (or click, in clocks and watches[1][2]) that engages one’s teeth. One’s teeth are uniform but asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the additional edge.
When the teeth are moving in the unrestricted (i.electronic. forward) direction, the pawl quickly slides up and over the softly sloped edges of one’s teeth, with a spring forcing it (frequently with an audible ‘click’) into the depression between your teeth as it passes the tip of each tooth. When the teeth move in the opposite (backward) direction, nevertheless, the pawl will capture against the steeply sloped edge of the first tooth it encounters, thereby locking it against the tooth and avoiding any further motion for the reason that direction.
Specifications
Angle of teeth 60°
Material S45C
Heat therapy Induction hardened teeth
Tooth hardness 50 ～ 60HRC