The hack saw is the name of a device used to cut metal or bone. It is a saw that comprises a strong and tough blade with fine teeth that is generally in the form of a single stretched metal piece fitted into a rectangular frame. The word hacksaw is believed to come from the Middle English word "hagge-saue" which was a type of saw. Hacksaws can be either medium to large sized or small. The larger ones have comfortable pistol like grips that offer a better hold. Smaller ones however are usually built into a tiny frame. Though the actual blade is brittle and easy to break these saws are very efficient when it comes to cutting hard objects of metal and even bone.
The hacksaw is a saw which you use to cut plastic or wood or tubes. You cannot can cut straight lines