Bandsaws are a power tool that have a looped metal cutting blade tensioned over 2 pulleys. The top pulley retains and guides the blade, while the lower pulley varies the speed. The blade runs in one direction rather than with the ‘up and down’ movement of a jig saw. Bandsaws are not suitable for cutting very thin sheet metal; a rule of thumb suggests the metal to be cut should be thicker than the depth of 3 bandsaw blade teeth, however they are excellent for cutting thin walled profiles such as box and angle.
Blades are available in different widths suited for different cutting requirements; thicker blades work well for thicker metal stock and straight cuts, whereas a thinner blade is better suited to cutting curves. Blades with a higher tpi provide a smoother cut edge whereas blades with a lower tpi make light work of cutting through thicker metal stock.
Bandsaws are available as cordless units, bench top models, and as freestanding floor models. As with most power tools, the range of extra features increases from standard settings on smaller DIY models to a fully comprehensive range of additional features available on the more professional models, extra features may include mitre cutting settings, more variable speed settings, and hydraulic descent in addition to standard manual descent. Bandsaw speed settings are measured in either metres per minute (mpm) or the more standard revolutions per minute (rpm).
Tips for cutting metal with a bandsaw.
- Ensure correct PPE including eye and ear protection is worn.
- Mark or score the cut line if necessary.
- Ensure that the blade is suitable for cutting metal and that it is correctly fitted and tensioned.
- Make sure all blade guards are in the correct position and free from defect.
- Adjust all settings for the type of cut being performed; such as speed and mitre angle for example.
- Connect the power and make sure all cables are out of the way of the blade, then start the machine.
- When using a bandsaw set in the vertical position, cutting is achieved by resting the metal on the plate and pushing it towards the blade while maintaining pressure. The blade can pass completely through the workpiece or the workpiece can be simply withdrawn, rotated and pushed towards the blade again to make additional cuts.
- If cutting an intricate design, it is advisable to make a series of relief cuts to reduce any binding on the blade.
- When cutting curves, it is best to start at the shallowest angle of the curve and work towards the steepest angle to reduce the risk of the blade veering off from the cut line. If both ends of the curve are shallow, make a cut from each end until they meet at the middle.
- For cuts using the hydraulic arm capabilities of some bandsaw models, place the metal on the support table and ensure it is firmly held against the rear guard, lower the arm to move the blade downwards through the workpiece.
- For cuts using a cordless bandsaw; ensure the workpiece is secure, line up the blade to the intended cut line and lower the blade into the metal. Once the cut has been made, stop the blade and withdraw.
- If the blade begins to stick or bind, stop the blade and apply some wax stick directly to the teeth of the blade.