Glossary · Hazards and harm
Shearing hazard
In machine safety, a shearing hazard is a mechanical hazard in which moving parts can cut or sever a body part by passing one another, or by passing close to a fixed edge.
- Machine safety
- Risk assessment
In one sentence
A shearing hazard exists where machine parts slide past each other or past a fixed edge with enough force to cut or sever fingers.
Example
A guillotine shear for sheet metal has a blade passing the edge of the fixed bed; a fixed guard with a narrow feed opening keeps hands out of the shear line.
How it applies
- Machine safety: Shearing occurs at blades and punches, but also in less obvious places: a sliding table passing a frame, a swinging arm passing a column, or a reciprocating part passing a guard edge. The forces are usually high enough to sever fingers.
- Guarding: Openings close to a shear line must respect safety distances, such as those in ISO 13857, so that fingers cannot reach it; see reach distance.
- Technical documentation: Identify shear lines in the risk assessment and in instructions for setting and tool changes, when guards may be open.
- Evidence: Record the guard openings near shear lines and the distances used to check them.
Shearing hazard vs. crushing hazard
In a crushing hazard, parts move toward each other. In shearing, they slide past each other. A press tool can do both.