Injuries due to contact with rotating parts can be severe. Collars, couplings, cams, clutches, flywheels, shaft ends, spindles, meshing gears, and horizontal or vertical shafting are some examples of common rotating mechanisms which may be hazardous. The danger increases when projections such as set screws, bolts, nicks, abrasions, and projecting keys or set screws are exposed on rotating parts, as shown in Figure 1 . In-running nip point hazards are caused by the rotating parts on machinery. There are three main types of in-running nips.
Parts can rotate in opposite directions while their axes are parallel to each other.
In the latter case the stock fed between the rolls produces the nip points. This danger is common on machines with intermeshing gears, rolling mills, and calenders. See Figure 2 . Nip points are also created between rotating and tangentially moving parts. See Figure 3 .