Spun Ground Rotary Broach Tool

Spun Ground Rotary Broach

Do you need to reduce the pressure on your rotary broaching operation, or get the material removal per side to a more practical dimension?

Rotary broach tools with spun ground diameters offer a number of advantages for optimizing the broaching operation at minimal cost. Trying to grind individual radii on the corners of hexagon and square broaches is not always practical, but the spun ground diameter is often an acceptable alternative. This diameter is calculated from the center of the form, and is slightly smaller than the sharp corner dimension of the given polygon or custom rotary broach form.

Adding a spun ground diameter to a broach removes the sharp corners from the form. If a broach is failing and chipping at the corners, the strengthened broach will be less likely to fail and likely improve tool life. For this design to work, Polygon extends the diameter the length of the form along the back taper of the broach.
The spun ground diameter also reduces the size of the chip to cut from the work piece. The smaller chips may require a smaller pilot hole depth and possibly be an opportunity to reduce the amount of drilling required. This small reduction often saves cycle time and money.

Because the chip size is smaller, the pressure required to push the chip is also reduced. The combined reduction of chip size and pressure may also have a beneficial effect on the work piece, the machine and the tools. Some forms may not be able to be broaches without a spun ground diameter.

The key to determining if a spun ground diameter will work for you usually has to do with the mating part. For example, if you are broaching a square hole for a custom socket, it is likely that the socket wrench driver has the sharp corners chamfered or ground off for easy assembly. In this case, there may be an opportunity to leave some material in the corners of the hole and it will not interfere with the function or space required from the mating part.

Standard hex and square broaches can be ordered with spun ground diameters. Simply specify the required diameter when ordering the broach. Custom ground broaches are not available for order online.

To request a quote on a Spun Ground Rotary Broach fill out our online quote form or call us at 239-628-4800.

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