Build Your Way to Success: Rock the STSC Exam 2025 - Be the Trendsetting Supervisor!

The tool rest and tongue guard on a bench grinder should be adjusted to a distance of 1/8 inch to 1/4 inch from the grinding wheel. This close proximity is crucial for ensuring safety and efficiency during grinding tasks.

When the tool rest is set within this distance, it allows for better support of the workpiece, reducing the risk of the workpiece becoming wedged between the wheel and rest, which can create a dangerous situation. Additionally, maintaining this gap helps to minimize the chances of sparks or debris flying out from the wheel without adequate protection.

The positioning of the tongue guard is also important; it should be positioned to prevent debris and sparks from reaching the operator while allowing enough clearance that the operator can work comfortably. A distance of 1/8 inch to 1/4 inch is optimal for safety and comfort.

Other options suggest wider gaps that either exceed the safe distance for tool rests or are not practical for effective grinding operations, making them less suitable for optimal safety and performance.