Glossary · Guards and machine motion
Self-adjusting guard
In machine safety, a self-adjusting guard is a guard that moves according to the workpiece and returns automatically to its protective position, so that only the part of the tool needed for the work is exposed.
- Machine safety
- USA
In one sentence
A self-adjusting guard opens only as far as the workpiece pushes it and closes by itself, but it still leaves a gap at the tool while material passes.
Example
The lower blade guard of a portable circular saw retracts as the saw enters the wood and springs back over the blade when the cut is finished.
How it applies
- Machine safety: Self-adjusting guards are used at a point of operation where workpiece sizes vary, for example on saws and jointers. The protection depends on the return mechanism working reliably.
- Maintenance: Dust, resin and wear can make the guard stick in the open position. The instructions should require a check that it returns freely before each use and name cleaning and replacement intervals.
- Human factors: Operators sometimes wedge the guard open to see the cut. Design for visibility, and warn against blocking the guard.
- Terminology: “Self-adjusting guard” is common in OSHA training material. ISO 12100 has no separate definition; classify the guard as a movable guard in European documents.
Self-adjusting guard vs. adjustable guard
An adjustable guard is set by a person and stays put. A self-adjusting guard is moved by the workpiece and returns on its own.