Friday, February 20, 2015

TECH TIP: Determining Bit Position for Optimal Squaring Results

When using 300 Series squaring tools in preparation for welding high purity tubing systems, you can direct the burr away from the polished ID bore for a better autogenous weld joint.

The way the tool bit is mounted in the bit holding slot can shift the .005” burr from the ID to the OD, or vice versa. The variable of bit position determines the effective shear angle of the cut.

Tri Tool’s premium DURABIT® squaring bits are ground with a high shear angle.

If the OD burr is excessive, positioning the tool bit to use the outside part of the cutting edge, (Low Shear) reduces effective shear which will reduce the OD burr.

Conversely, moving the bit as far “out” as possible (the tip of the edge must remain inside the bore of the tube) will provide the most shear angle (High Shear) reducing the burr on the tube ID.

For tubing with an ID greater than .50”, the tool bit can be mounted backwards in the tool bit slot (Maximum Shear) for the greatest amount of shear action.

Relatively small changes in bit position can make a big difference so make sure to experiment to see what works best for you.