How to Use a Torch? | Two Very Different Kinds

Using a torch means either turning on the iPhone or iPad flashlight through Control Center, or safely operating a fuel torch for cutting or soldering — and the safety rules for the fuel kind are non-negotiable.

For the full breakdown, see our best Mechanics Torch guide.

On Apple devices it’s the built-in flashlight, a one-tap utility. For metalwork, plumbing, or cutting, it’s a tool that runs on butane, propane, MAPP gas, or acetylene mixed with oxygen.

The Apple Torch: Turning On The iPhone and iPad Flashlight

You control it from Control Center, the screen overlay you reach with a swipe.

To turn it on, open Control Center — swipe down from the top-right corner on an iPhone X or later, or swipe up from the bottom edge on an iPhone 8 or earlier. Tap the flashlight icon (a small torch, circle top-left by default). The icon turns blue, and the LED next to the camera lens glows. Tap it again to turn it off.

On iPhone 15 Pro and iPhone 16 Pro models, you can assign the Action Button to the torch. Go to Settings > Action Button, swipe to the Torch icon, then press and hold the side button to toggle it on and off.

Using a Cutting Torch or Fuel Torch Safely

A fuel torch — whether it’s a small butane pencil torch, a propane torch for soldering copper pipe, or an oxy-acetylene rig for cutting steel — follows the same basic safety and operating principles. The exact procedure varies by manufacturer, so always defer to the specific manual for your tool, but these general steps apply to almost every type.

Setting up and lighting the torch:

• Hold the fuel cylinder upright. Screw the torch head onto the cylinder valve by hand until snug. Do not overtighten — the threads do the seal, not brute force.
• If you suspect a leak, brush soapy water on the connection. Bubbles mean a leak; tighten the fitting or replace the cylinder and ventilate the area before trying again.
• Open the gas control knob slowly (a quarter to half a turn). Then use a spark lighter or striker to ignite the gas — not a cigarette lighter or match. Your hand will be too close to the flame with a standard lighter, and the striker is safer.

Heating and working with the flame:

• Adjust the gas control knob until you get a stable blue flame with a sharp inner cone. That inner cone is the hottest part.
• To heat a workpiece, keep the tip of the inner blue cone about 1/2 to 1 inch from the metal. Move the flame in small circles or back and forth for even heating.

Shutting down and storing:

• Close the gas control knob at the torch head first. Let the torch cool naturally — never dunk it in water.

What To Do If Something Goes Wrong

Two specific failure types require immediate action.