Sword punches, also known as Straight, Narrow and Arrow Punches are characterized by a long thin tool with no relief cut into the profile. As shown in the image to the left sword punches are often used to bend deep into a symmetrical profile to form the last bend which closes the profile. In addition to regular profiles this type of forming is commonly used to bend tubing. This is useful when a custom size or wall thickness is needed and isn’t available from a steel supplier. This happens with odd sizes or if the tubing doesn’t have a rectangular profile. As you can see a sword punch would be capable of forming all but one side of a tube. The last edge is then typically welded and polished to match the other edges.
When selecting a sword punch it is very important to understand that the tonnage this type of tooling can withstand is going to be significantly less than that of standard profile tools. Many times you will see tonnage limits of 10-15 Tons Per Foot, about half of that of standard punches. Because of this Air Bending is the preferred method of bending with this tool, especially for heavier gauges. Bottom Bending is possible on lighter gauges through proper material and die selection. Coining should only be attempted with thin gauges and with careful consideration.