A power hacksaw is an electric version of the classic hacksaw that is used to make cuts in metals. Hacksaw blades come in different sizes and strengths depending on the type of metal material you need to cut through. Blades are sized depending on the number of teeth on the blade per inch. Common sizes include 14, 18, 24 and 32. Higher numbered blades are used for hard, thin metals while lower numbers are best for soft metals. As with all cutting instruments, changing blades when they become dull or to compensate for the type of material being cut is essential to safe use and quality cuts.
Unplug the power hacksaw from its power source. Make sure the saw is unplugged and turned off before attempting to change the blade as touching the blade with the power on could result in serious injury.
Locate the wing nuts on the front and rear ends of the hacksaw blade assembly. Loosen the nuts by hand until the blade is loose enough for you to slide it out of the blade frame.
Insert the new blade into the blade frame so that the blade teeth face away from the blade handle. Hook the holes on the front and back of the blade onto the small pins located at the front and rear of the blade frame. Tighten the wing nuts to hold the blade securely in place on the blade frame.
Plug the power hacksaw in and turn it on. Wear appropriate personal safety equipment (safety goggles and gloves) and make a practice cut onto scrap metal to test the tension of the blade. Watch the blade during the cut to see if it arches or bows; turn the machine off, unplug it and loosen the wing nuts slightly to correct the tension.