Simple Techniques for Cutting Metal Conduit Perfectly

Installing metal conduit for electrical wiring or plumbing requires making precise, clean cuts to ensure proper connections. While cutting metal conduit may seem intimidating, with the right tools and techniques, DIYers can make professional-quality cuts. This comprehensive guide covers everything needed to cut conduit like a seasoned pro.

From how to choose the ideal conduit for the job and gather the correct tools to detailed cutting, deburring, and finishing steps, you'll learn insider techniques used by experienced electricians and plumbers. With a little practice, you'll be able to accurately cut metal conduit to exact measurements quickly.

Choosing the Optimal Metal Conduit Type

Metal conduit comes in a range of types, each designed for specific applications and environments. The most common are:

• Rigid Galvanized Steel - The thick walls and galvanized coating make this conduit highly durable for exposed outdoor applications. It's the most widely used conduit type.
• Aluminum - With decent strength yet lightweight properties, aluminum works well for exposed indoor or outdoor installations.
• Intermediate Metal Conduit (IMC) - Similar to galvanized steel but with thinner walls, IMC suits indoor structured wiring runs.
• Electrical Metallic Tubing (EMT) - EMT has a thin profile but is rigid enough for most indoor, concealed wiring.
• Flexible Metal Conduit - The bendable design makes flexible metal ideal for connecting moving parts like motors.

Consider the environment (indoor vs. outdoor use) along with the wiring or piping layout. Galvanized steel stands up best outdoors while EMT suits indoorjobs. Flexible metal is perfect for retrofitting existing spaces. Match the material and type to your specific project requirements.

Sizing Conduit Correctly

Conduit size depends on the number and type of wires contained. Undersized conduit strains wiring while oversized wastes money. Follow National Electric Code (NEC) recommendations:

• Size conduit based on wire gauge, insulation, and number of wires.
• Use trade sizing for conduit diameters (1/2-inch, 1-inch, etc.)
• Factor in derating if wires overfill the conduit by 40% or more.
• Increase conduit size whenever wire number exceeds nine.

Consider using conduit sizing calculators to determine the optimal diameter. Match conduit strength and volume to your wiring needs.

Gathering the Essential Conduit Cutting Tools

Having sharp, quality tools designed for cutting metal is vital to success. Must-have tools include:

• 32 TPI Hacksaw - The go-to for manual cutting. Select a hacksaw with 32 teeth per inch (TPI).
• Tubing Cutter - Quickly and neatly severs small 1/2 to 1 inch conduit.
• Miter Box - Holds conduit steady for precise angled end cuts.
• Half-round File - Smooth cut edges and remove burrs.
• Reamer - Deburrs interior to prevent wire snags.

For faster cuts, circular or band saws equipped with fine-tooth metal cutting blades are excellent power tool choices. Always use work gloves and safety glasses when operating saws and cutting conduit.

Technique Tips for Manual Hacksaw Cutting

Manual hacksaws equipped with fresh 32 TPI blades can sever conduit quickly when used correctly:

• Keep the hacksaw frame upright 90deg to the conduit.
• Allow the blade teeth to cut with light downward pressure.
• Use smooth, full strokes the full length of the blade.
• Lubricate blades occasionally with light oil for easier cutting.
• Let the hacksaw do the work, don't force the blade.

Proper hacksaw technique minimizes cutting time while avoiding broken blades or damaged materials.

Measuring and Marking Cut Lines Accurately

Precision measurements and markings ensure conduit gets cut to the correct length. Follow these steps:

1. Measure and calculate the exact conduit length required for the run.
2. Account for any bends, threading, connectors when measuring.
3. Avoid measuring conduit that is already installed - remove to measure.
4. Use a tape measure and marker to denote straight cut lines.
5. For angled cuts, measure and mark precise mitered angles.

Remember, always measure twice and cut once! Verify measurements before cutting to prevent wasteful errors.

Cutting Techniques for Secure, Straight Cuts

With measurements marked, you're ready to make the cut. Follow these techniques:

• Secure conduit tightly in a vise or miter box to prevent unwanted movement.
• Position your hacksaw/cutter at a straight 90deg angle to the conduit.
• Apply firm pressure when cutting, allowing the tool to do the work.
• Use smooth, steady strokes minimizing blade binding.
• Make small relief cuts on round conduits before cutting all the way through.

Work slowly and deliberately, don't rush the cut. For power saws, let the blade reach full speed before cutting. With practice, you'll perfect straight, fast conduit cuts.

Cutting Flexible Conduit

Flexible metal conduit requires special care when cutting. Follow these methods:

• Method 1 - Use a fine-blade hacksaw, gently slicing through the diameter while rotating the conduit up and down to ensure a smooth cut.
• Method 2 - Utilize a scroll saw, moving the conduit into the blade for a clean cut. This is less ideal as it may leave ridges inside the conduit.

Avoid applying too much pressure when cutting flexible conduit to prevent collapsing or deforming it. Take it slow.

Deburring and Preparing Cut Conduit Ends

Proper cut end finishing is critical for smooth wire pulls and leak-free connections. Here's how:

1. Inspect cuts and use a file to smooth any rough edges or remnants.
2. Insert a reamer into the conduit end, rotating to remove interior burrs.
3. Clean threaded ends and apply sealant to prevent water infiltration.
4. Cap ends to prevent debris entering before installation.

Taking time to completely deburr and prep your cut ends pays off through enhanced safety and performance.

Conduit Cutting Safety Tips

Working with metal conduit poses certain safety hazards. Keep these tips in mind:

• Always wear thick gloves and eye protection when cutting.
• Maintain a sturdy grip on tools and watch for pinch points.
• Secure conduit with clamps to prevent binding or slippage.
• Work in a clean, well-lit area clear of clutter and trip hazards.
• Avoid cutting energized conduit or near live wires.

Forcing blades and rushing through cuts can lead to binding or slipping. Stay focused and cut deliberately to prevent accidents.