What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
Small holes are harder to cut cleanly than they look. A handheld plasma cutter can pierce and cut them quickly, but the torch’s arc, nozzle size and your hand movement all matter more as the hole gets smaller. A hole that is too tight for the torch to enter should be started from the edge or pierced; trying to force the torch into it risks damaging the consumable and leaving a rough, tapered opening.
Check the cutter and material
Read the cutter manual for its recommended material thickness, cutting amperage, air pressure and pierce height. A machine’s advertised maximum cut is not a promise of clean, precise holes at that thickness. Small openings are easiest in thinner sheet, where the arc has less metal to remove and is less likely to blow the edge away. On thicker plate, expect more dross, a wider kerf and a greater chance of a hole that needs drilling or grinding to finish.
Use clean, dry compressed air at the pressure and flow specified by the manufacturer. Water or oil in the air line can shorten consumable life and make the arc unstable. Keep the work clamp on clean metal, close to the cut, and make sure the workpiece is supported without touching a flammable surface. Remove paint, rust and scale around the cut if they interfere with electrical contact or visibility.
Choose a hole-cutting method
For a very small hole, the torch body may be wider than the finished opening. In that case, mark the hole, pierce at its center and move the torch around the mark, keeping the arc on the waste side of the line. If the opening is large enough for the nozzle to travel around it, use a steady circular motion instead. A circle guide or template can help, but it must not obstruct the torch or catch the arc.
Some cutters offer a drag shield or a guide designed to keep the torch at the correct distance. These can improve control, but do not assume a general-purpose straight-edge guide will produce a perfect circle. For repeated, accurate holes, a drill press with a suitable metal-cutting bit or hole saw may be a better tool. Plasma is useful when the material is too thick or awkward to drill, or when speed matters more than a ready-to-use finish.
Set up and cut
First, transfer the hole center and diameter to the workpiece. Check both sides for obstructions, and clamp the metal so it cannot shift as the cut breaks through. Wear a properly rated welding helmet, gloves, flame-resistant clothing and safety footwear. Plasma cutting produces intense light, hot metal and fumes; use suitable ventilation, and keep bystanders clear of the arc and sparks.
Set the machine according to its manual and select a current appropriate to the material, rather than defaulting to maximum output. Fit undamaged consumables. Hold the torch at the specified standoff, or rest the drag shield on the work only if the manufacturer permits it. Start the arc at the center for a pierced hole, angle the torch slightly away from your body, and let the arc pass through before moving around the marked circle. Once the arc is through, travel smoothly at a consistent speed.
Moving too slowly can make the arc wander, enlarge the hole or leave heavy dross underneath. Moving too quickly can leave an incomplete cut or a ragged bridge of metal. If the arc sputters, stops or will not pierce, stop and check air supply, ground connection, consumable condition and machine settings rather than repeatedly triggering the torch. Allow the metal to cool before checking the opening.
Plasma cutting or drilling?
| Method | Best for | Trade-off |
|---|---|---|
| Handheld plasma cutter | Awkward parts, thicker stock and quick rough openings | Needs practice; small holes may be tapered or require cleanup |
| Drill and metal-cutting bit | Small, round holes in thinner, accessible stock | Slower on thick plate; needs secure clamping and suitable cutting fluid when specified |
| Hole saw | Repeatable larger holes in sheet or moderate-thickness material | Can snag, heat up or wear quickly if speed and support are poor |
If plasma is the right choice, compare cutters by their rated clean-cut capacity, air requirements, consumable availability and torch design—not just peak amperage. A basic unit may be enough for occasional holes in thin steel; paying more for a machine is worthwhile only if its duty cycle, cut capacity or torch features match your work. Browse handheld plasma cutters and check that your compressor can meet the specified air flow at operating pressure.
For occasional small holes in thin sheet, a metal-cutting drill bit can be cheaper and produce a cleaner opening with less finishing. For larger circles, a metal-cutting hole saw is often the more controlled option, provided the work can be clamped securely.
Clean up and troubleshoot
After the workpiece cools, remove dross with a file or grinder and check the hole with a caliper or the part that must fit through it. Plasma cuts leave a kerf: the material removed by the arc. Account for it by keeping the arc on the waste side of the mark. If the opening is undersized, enlarge it gradually; taking too much off one side can leave the hole out of round.
A bevel on the cut edge can come from torch angle, incorrect standoff, unsuitable travel speed or worn consumables. An oversized hole often means the torch paused, wandered or followed the wrong side of the line. If accuracy matters for a fastener, bearing or fitted component, cut slightly undersize and finish with a drill, reamer or file rather than expecting a handheld plasma cut to be precise straight off the torch.