A hacksaw is a saw with fine teeth and with a blade under tension in a frame; it is in most cases used to cut hard materials like metal. A hand held hacksaw consists of an arch made of metal, with a grip handle with a removable hacksaw blade. The hacksaw blade can be mounted with the teeth facing towards or away from the handle, resulting in cutting action or either the push or pull stroke.
The hacksaw comes in many different forms and sizes depending on the work being carried out. Purposes range from small manual chores like cutting metals to large scale labor like cutting logs. For such you may require the use of a power hacksaw.
Power hacksaws are used to cut large sections of metal such as steel and logs. Having to cut a diameter of 10/15 mm might be a very tedious and strenuous activity with the normal hand held hacksaw blades. Therefore, the power hacksaw has been designed to carry out the difficult and sometimes time consuming task.
All power hacksaws are basically similar in design. Being quite a large tool, the power hacksaw is mostly stationery. An ordinary power hacksaw consists of the following:
The base of the saw contains a coolant reservoir and a pump for conveying the coolant to the work. A table supporting the vise and the metal being sawed is located on the top of the base of the power hacksaw and is usually referred to as the base.
The vise of the power hacksaw is adjustable so that various sizes of the object may be held. The size of the saw is determined by the largest piece of metal that can be held in the vise and sawed.
The frame of the power hacksaw supports the blade of the machine and is designed so that the so that the saw blade contacts the work only on the cutting stroke. The cutting stroke is on the draw or back stroke.
Power hacksaw blades differ from the normal hand hacksaw in that they are generally heavier, longer and have fewer teeth per inch. Power hacksaw blades are discarded when they become dull or sharpening is no longer applicable.
Materials used in manufacturing hacksaw blades are high-speed molybdenum steel and high-speed tungsten steel. On some blades, only the teeth are hardened leaving the body of the blade flexible. In other blades, the hardening is throughout.
The power hacksaw is primarily designed for straight line sawing. A typical sawing operation goes as follows.
- Select a hacksaw of proper length for the machine and proper pitch for the material to be cut. Install the hacksaw blade with the teeth pointing downwards and towards the motor end of the machine.
- Check the alignment of the vise and hacksaw blade and mount the work piece in the vise.
- Check the stroke of the power hacksaw and adjust if necessary. Readjust the position of the vice of necessary. Position the hacksaw blade about ¼ inches above the work piece and set the feed control to its highest settings.
- Set the desired speed of the machine.
- Start the machine. Let the hacksaw blade feed slightly into the work piece for about ¼ inches.
- Permit the hacksaw to cut completely into the work piece.