Draper Expert Bi-metal Hacksaw Blades - 300mm, 18tpi (Pack of 10) - Draper - 19347

18tpi (teeth per inch) blades are best suited for cutting medium-thick sections of metal, generally ranging from 3mm to 10mm in thickness. This includes materials like steel, aluminium, and copper pipes or bars.

No, these bi-metal hacksaw blades are specifically designed for cutting metal. Using them on wood will not be effective and may damage the teeth.

Replace the blade when you notice a significant decrease in cutting speed, if it requires excessive force to cut, or if the teeth appear worn or damaged. An audible 'singing' or 'screaming' sound during a cut can also indicate a dull blade.

Bi-metal construction means the blade is made from two different types of metal: a high-speed steel (HSS) strip for the cutting edge, known for its hardness and heat resistance, and a flexible carbon steel backing to prevent the blade from breaking.

While 18tpi can cut thin sheet metal, a blade with a higher tpi (e.g., 24tpi or 32tpi) would generally provide a smoother cut and prevent teeth from snagging or stripping on very thin materials.

It's best to store the blades in their original packaging or a dedicated blade storage case to protect the teeth from damage and prevent accidental cuts.

Ensure the blade is correctly tensioned in the hacksaw frame. Avoid excessive downward pressure, especially on the backstroke. Check for obstructions in the material being cut.

Verify the blade is installed with teeth pointing correctly (away from the user). Ensure the workpiece is securely clamped. Check that the hacksaw frame is straight and not bent.

The blade may be dull and needs replacement. Ensure you are using the correct tpi for the material thickness. Clean any debris from the teeth.

This can happen if the tpi is too low for the material thickness or if the material is very soft. Ensure the blade is not being forced through the material too quickly. Check that the correct tpi is selected for the job.