Glossary · Guards and machine motion
Adjustable guard
In machine safety, an adjustable guard is a guard that can be adjusted to accommodate different workpiece dimensions or operations. It is adjustable as a whole or has adjustable parts, and it keeps its setting during a given operation.
- Machine safety
- Human factors
In one sentence
An adjustable guard is set by the operator to suit the workpiece; it protects only when set correctly, so instructions must say how to adjust it.
Example
On a bench-mounted band saw, the upper blade guard is lowered to just above the workpiece height before each cut, leaving only the part of the blade needed for cutting exposed.
How it applies
- Machine safety: An adjustable guard is used where the hazard zone cannot be fully enclosed because material must pass through it, for example at a saw blade or a drill spindle. It restricts access but relies on the person setting it correctly.
- Human factors: A guard that is awkward to adjust tends to be left in its most open position. Tool-free, repeatable adjustment and clear markings reduce this bypass behavior.
- Technical documentation: The operating manual must describe how to set the guard for each operation, the maximum permitted opening and the check before starting. State the residual risk at the exposed part of the tool.
- Evidence: Record in the risk assessment why a fixed or interlocking guard was not practicable and which openings were assessed.
Adjustable guard vs. self-adjusting guard
An adjustable guard is set manually and stays in position during the operation. A self-adjusting guard is moved by the workpiece itself and returns to its protective position automatically.