Cutting metals with an ordinary manual hacksaw is indeed a daunting task. Not only is it a waste of body energy, but it is also time consuming. The power hacksaw cuts metals with relative ease and far faster than doing it by hand. However, its blade may eventually be dulled from use or damaged due to improper alignment or fixing of the guides. If you have basic tool repair knowledge, replacing the blade is a do-it-yourself job.
Visit your local hardware store to determine the proper blade to buy. Consider its length and thickness: A blade that is too long will not provide adequate force, while a shorter one will not be able to handle the desired tasks and may even damage the tool. A too-thick blade will not fit properly with the dampers that hold it in position, while a thinner one is vulnerable to breaking. Make sure the blade matches your model power hacksaw, and if possible bring the broken blade with you to the store.
Remove the old blade using the hexagonal tool to unfasten the dampers holding the blade. Slide the blade out of position very carefully, because a minor slip could cause a serious cut due to the sharpness of the blade. Be sure to dispose of the old blade properly according to the manufacturer's recommendations and local waste disposal and safety codes.
Slide the new blade carefully in position until it fits perfectly in the notch. Make sure the blade is properly aligned according to the manufacturer's instructions to reduce the risk of breaking. Use the hexagonal tool to refasten the dampers in position. Secure the dampers tightly so the blade can not come off when you are operating the power hacksaw.
Test the new blade by using the power hacksaw to cut a piece of metal. If it does not work appropriately, unscrew the dampers and realign the blade accurately.