Round and Shaped Hole Broaches
Rotary Broach Tools create hexagon shapes in metal parts.
Press Release Summary:
Designed to fit into GT Series broach tool holders, Hexagon Rotary Broach Tools create holes used for hexagon keys or Allen wrenches. Pressure relief holes allow air, coolant, cutting fluids, and other materials to escape from hole when broach is pushed into it. Broaches have sharp corners, but can be altered to have round corners to minimize pressure on machining operation. In addition, broaches can be coated to optimize wear, and rake angle can be altered to optimize cutting action.
Original Press Release:
Hexagon Rotary Broach Tools
Fort Myers, FL - Polygon Solution's hexagon rotary broach tools are used for creating hexagon shapes in metal parts. The standard hexagon broach fits into Polygon's GT series broach tool holders and other commercially available tool holders. Various options are available when ordering hexagon rotary broaches. Rotary broaching often eliminates secondary operations.
Most hexagon shaped holes are not very deep. Typical applications include fasteners and shaft extensions. These holes are usually used for hexagon keys or Allen type wrenches used to rotate parts. Standard hexagon sizes are available to meet a wide variety of machining standards and accept these hexagon keys.
The typical hole is about the same depth as the flat-to-flat dimension of the hexagon. Most of these holes are also blind holes; they are not through holes. Therefore, one challenge while machining the form is to allow air, coolant, cutting fluids and other materials to escape from the hole when the broach is pushed into it. This is accomplished by means of pressure relief holes available as a standard feature. Only micro size broaches do not include the pressure relief hole. Polygon's GT Series rotary broach holder has a mating pressure relief hole to completely allow fluid and air to escape.
The greatest feature of a rotary broach is the ability to cut sharp corners into a blind hole. Hexagon rotary broaches have sharp corners, but can be altered to have round corners to reduce pressure on the machining operation. When the broach reaches the bottom of the hole, a decision must be made about how to deal with the chips. The chips could be left in the hole, or removed by returning to the hole with a drill or end mill to clean in out.
Various options are available to improve broach performance. Premium materials are available to increase the hardness of the broach. Rotary broaches can also be coated to improve wear. The rake angle can also be altered to try to improve cutting action. In some cases, no rake angle may even be the best solution. If a premium broach holder is not available, additional port holes can sometimes be added to the broach to reduce pressure.
Spun ground diameters remove the sharp corner from the broach and improve tool life. Corner chipping is the most common form of tool failure. The small radius on the corner is often enough to reduce the size of the chip, but not create an interference condition with the hex key. If tight tolerances are required, hex broaches can be ordered in any dimension close to standard sizes. Tight tolerances can also be requested when ordering.
Double hexagon rotary broach tools are available, but require more work to manufacture than standard hexagons. Double hex broaches are usually ordered as a custom broach, and the inside radius needs to be verified.
Rotary broaching does have size limitations. Depth of form and strength of the material often dictate the success of this type of broaching operation. Other important factors include pilot hole size and machine thrust capability. While forms around a quarter inch can easily be accomplished in aluminum, brass and mild steels, broaching the same form in stainless steel or titanium can be much more difficult. Forms larger than one inch are considered very difficult.
Standard hexagon rotary broach tools can be ordered online broach store.
For more information about rotary broaching, please contact Polygon Solutions Inc.
For the latest news, please read our Rotary Broaching Blog
