Review: Mill Safety

What are the three components of the fire triangle?

• Fuel, flame, and pressure

• Oxygen, spark, and smoke

• Heat, gas, and friction

• Oxygen, fuel, and heat

Answer explanation

The fire triangle consists of oxygen, fuel, and heat. Removing any one element extinguishes the fire. Flame and spark are products of combustion, not triangle components.

Covering a fire with a lid or blanket extinguishes it by removing which element?

• Heat

• Fuel

• Oxygen

• Ignition source

Answer explanation

A lid or blanket cuts off the oxygen supply. Cooling removes heat, and shutting off supply removes fuel.

Which milling practice is unsafe on a machine without backlash control?

• Slot milling

• Face milling

• Conventional milling

• Climb milling

Answer explanation

Climb milling pulls the workpiece into the cutter. Without anti-backlash control, the table can lurch and break the tool.

Which document lists safe handling information for shop solvents and coolants?

• Machine operator manual

• Job traveler document

• Safety Data Sheet (SDS/MSDS)

• Shop tool catalog

Answer explanation

The SDS (formerly MSDS) provides hazard, handling, and first-aid information for chemicals. Operator manuals and travelers cover machining procedures, not chemical safety.

A chip is lodged under the upper eyelid. What is the correct first-aid step?

• Pull the top lid over the bottom lid

• Apply firm pressure to the eyeball

• Flush the eye with compressed shop air

• Rub the eye to dislodge the chip

Answer explanation

Pulling the top lid over the bottom lid lets the lower lashes brush the particle out gently. Rubbing can scratch the cornea and compressed air can embed the chip deeper.

What is the correct first-aid response for a minor cut that is bleeding?

• Apply a tourniquet above the cut

• Rinse the wound with cutting fluid

• Wrap loosely and continue working

• Apply direct pressure to the wound

Answer explanation

Direct pressure controls minor bleeding effectively. Tourniquets are reserved for severe, life-threatening bleeding only and are not appropriate for minor cuts.

Why must oily rags be stored in a closed metal container?

• To prevent coolant from evaporating

• To comply with inventory procedures

• To keep them clean for reuse

• To prevent spontaneous combustion

Answer explanation

Oxidizing oils generate heat that can self-ignite. A sealed metal container limits oxygen and contains any resulting fire.

How should an operator approach a workpiece with a rotating face mill?

• At full hand-feed rate

• Quickly to reduce rubbing

• By plunging straight down

• Slowly and from the side

Answer explanation

Approaching slowly from the side prevents shock loading the cutter and allows time to react if something goes wrong.

Before checking part dimensions on a mill, the operator should:

• Slow the spindle

• Stop the spindle

• Raise the knee

• Engage power feed

Answer explanation

Always stop the spindle before measuring or reaching near the cutter.

Which action is incorrect when treating a minor cut in the shop?

• Applying firm direct pressure

• Covering with a clean dressing

• Seeking further first-aid care

• Applying a tourniquet immediately

Answer explanation

Tourniquets are reserved for severe, life-threatening bleeding only. Minor cuts require direct pressure and a clean dressing, not tourniquet application.