At Tri Tool, we are the tool bit experts, and especially when it comes to our tube squaring machines. We have three basic cutting edge geometries which function well on most common tubing materials. Selection of your tool bits should be based on tubing material, how critical it is to have a near burr-free end and tubing size. Here is some information you might need for your next tube squaring project and selecting the perfect tool bits:
- STANDARD ENTRANCE ANGLE BITS are used for carbon steel. They also function well on some stainless steel applications where a near burr-free end is not critical and will provide longer bit life.
- HIGH ENTRANCE ANGLE BITS are the most suitable geometry for 90% of all stainless tubing.
- EXTRA HOOK ANGLE BITS are good for very soft stainless steels including materials like 316L that have been bright hydrogen annealed, vacuum annealed or annealed and electro-polished. As drawn tubing normally runs above 80 Rb versus as low as 76 Rb for annealed and electro-polished low carbon stainless steels. Electro-polished stainless steel has a micro-thin surface which is high in chromium and nickel making it very soft but tough and difficult to cut without a burr.
- TALL TOOL BITS measuring .969” (24.5mm) are used for 3/16” (4.76mm) or less tubing. A tall tool bit also provides cutting advantages for wall thicknesses less than .020” (.5mm) because the taller bit will cut closer to the collet face, minimizing undesirable flexing of the tubing from the cutting pressure. Note that using a tall tool bit requires more time and care to achieve the proper tool bit position.
- M-42 TOOL STEEL BITS are used for exotic alloys where high heat resistance is required to avoid burring the cutting edge. An M-42 bit can also improve the life expectancy of the bit under some conditions on stainless steel. However, because M-42 tool is more brittle than M-2 there is a greater risk of damaging the tool bit when installing the tubing in the tool and loss of tool bits from damaged edges may not offset the improved cutting life.
- EXTRA HOOK ANGLE BITS may be required for some exotic alloys, as well as the use of M-42 tool steel for improved heat resistance.
While the selection of the best bits to use may sound confusing, it is important to remember that our extensive experience with the various tube alloys and bit geometries has been acquired over many years of working closely with our customers. Our expert tool bit design assistance can help you with this decision.