Why is the cutting tube so different to solid?
Much of the cutting of tubes in the fabrication & welding industry is cut by bandsaws and this can be done quite economically.
The reason for this is that they are designed to hold a bundle of tubes (nesting) so that many tubes can be cut at the same time (preferably with bundle clamps). Cold saws can be used but they are limited in the size of the material that they can cut. Also, the blade is thicker, so more material is removed during cutting.
As we would say the bandsaw is the ‘workhorse’ in the fabrication industry and it is usually found in every workshop and comes in a large range of sizes even down to portable machines that the tradesmen take to site.
Cutting tube.
Sawing tube and pipe is more difficult than sawing a solid bar and plate because the saw blade is doing two types of cuts. To explain this: As the blade enters or exits the tube, it is cutting a large section of steel very similar to solid (see diagram 1). As the blade cuts through the middle of the workpiece and penetrates the inner wall of the hollow, it is cutting two thin solids with a space between them (see diagram 2). We call this an interrupted cut. See below diagram to explain this:
When cutting tubes in bundles it is more complicated again as it increases the interruption for the blade. However, the biggest issue that saw operators face with bundle cutting is movement between workpieces. See below on ‘Vice Pressure’ to help with this issue.
So what should I do when cutting tube?
Choose the right blade
This leads to what blade do I use for cutting tubes versus solid? Consideration needs to be given to the size of the material being cut and the type of material, so blade manufacturers make a range of blades to suit various materials with different numbers of teeth to suit the size of your material that you are going to cut. They provide handy tables for each type of blade, so you know which one to choose, if you are cutting bundles at a time a different table applies. Check out our Tooth Selection Guide
Bandsaw settings
Even with the correct blade, the saw must be adjusted properly to cut the tube and pipe successfully.
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