Start with the material and the cut
The best way to cut metal depends on its shape and thickness. Thin sheet, flat bar, round rod, square tubing and angle iron all behave differently, and a tool that is ideal for one can be awkward or unsafe for another. Before picking a tool, decide how accurate the cut needs to be, whether heat and sparks are acceptable, and how much metal you have to remove.
Whatever you choose, secure the work first. A piece that can shift will bind the blade or wheel, spoil the cut and sometimes cause injury.
Hand methods
Hacksaws
A hacksaw is a frame that holds a thin blade under tension. It is slow but quiet, cheap, makes no sparks and gives you a lot of control. Blades are described by teeth per inch, and the usual guidance is that at least two or three teeth should be in contact with the material at all times. That means:
- Coarser blades (fewer teeth per inch) for thick solid stock and softer metals.
- Finer blades (more teeth per inch) for thin sections, tubing and angle.
Too coarse a blade on thin tubing tends to catch and strip teeth. Too fine a blade on thick stock clogs and cuts slowly. Install the blade with teeth pointing away from the handle, so it cuts on the forward stroke, and tension it firmly. Use steady, full strokes and lift slightly on the return. Bimetal blades generally last longer than plain carbon ones, though blade quality varies.
Snips
Snips shear thin sheet metal like heavy scissors. Straight-cut snips handle straight lines and gentle curves, while left-cut, right-cut and offset aviation-style snips are designed for curves in a particular direction. Color-coded handles are a common convention for these, but check the markings on your own pair.
Snips are best on thin sheet only; thicker metal needs a different tool. Forcing them risks a bent blade or a slipped hand. The cut edges are very sharp and often curl, so handle them carefully, and expect to clean up the edges afterward as described in the deburring article.
Other hand options
Tin snips, bolt cutters, tube cutters and files all have their places. A tube cutter makes a square, clean cut on pipe, and bolt cutters shear rod and chain, though they can leave a crushed end.
Powered methods
Abrasive cutoff wheels
A thin abrasive disc spinning at high speed cuts steel, bar and tubing quickly. These wheels are used on angle grinders and in dedicated cutoff saws. They are fast, but they are also loud, throw a lot of sparks and produce hot, sharp debris. The main hazards are:
- Wheel breakage. A thin wheel can shatter if it is twisted, pinched, dropped or run beyond its rated speed.
- Kickback. A binding wheel can jump out of the cut.
- Sparks and fire. Sparks can ignite sawdust, rags, solvents and other combustibles.
- Noise and dust. Hearing protection and a dust mask appropriate for the work are sensible. Hearing and dust protection should be treated as standard whenever these tools run.
Use a cutoff wheel only for cutting, not for side grinding, and keep the guard in place. The safe use of a grinder with such wheels is covered in the angle grinder article.
Reciprocating saws, jigsaws and bandsaws
A reciprocating saw with a metal-cutting blade is useful for rough cuts, pipe and demolition. Choosing the correct jigsaw blades for metal lets a jigsaw handle thin sheet and curves, while a bandsaw gives clean, straight cuts on bar and tube with less heat and spark, though it is a larger investment.
Metal-cutting blades generally have finer teeth than wood blades, and running at a lower speed often helps them last. Check the manufacturer’s recommendations for blade selection and speed.
Comparing the options
| Method | Speed | Control | Sparks and heat | Best for |
|---|---|---|---|---|
| Hacksaw | Slow | High | None | Rod, tube, small jobs |
| Snips | Fast on thin sheet | Moderate | None | Sheet metal |
| Cutoff wheel | Very fast | Moderate | Heavy | Bar, angle, tubing |
| Reciprocating saw | Moderate | Lower | Moderate | Rough cuts, pipe |
| Bandsaw | Moderate | High | Low | Clean straight cuts |
The ratings are general. Specific results vary with blade or wheel choice, metal type and your own skill.
Safe habits for any cutting
- Wear safety glasses, and add a face shield for powered cutting.
- Clamp the work securely, with the cut line supported on both sides where possible.
- Keep sparks pointed away from people and flammable items, and keep the area clear.
- Let the tool do the work and avoid forcing or twisting it in the cut.
- Unplug the tool or remove the battery before changing blades or wheels.
- Wear gloves to handle cut pieces, but not when a rotating tool could catch them. Loose gloves and sleeves can be pulled in.
- Let cut pieces cool before handling, since they can be hot.
When a lot of cuts are planned, think about whether the extra speed of a power tool is worth the added risk. For occasional cuts on small stock, a hacksaw is often the safer and perfectly adequate choice.
After the cut
A freshly cut edge is nearly always rough. It may have burrs, sharp slivers and heat discoloration. Cleaning it up is the step that makes the piece safe to handle and ready for drilling, fitting or welding.
This article is general information. Follow the manual for your specific tools.