A pre punched hole is required as a one hit pierce and extrude gives poor hole quality and has limited adjustment on the machine.
Extruded tapped hole sheet metal.
First prevailing off torque is an indication of locking torque and resistance to vibrational loosening and is favorably high for extrude tite screws in thin sheet metal.
The following illustration shows the extruded hole geometry.
In low carbon steel sheet metal the minimum radius of a bend should be one half the material thickness or 0 80 mm.
Creating an extruded hole using a punching process requires extreme pressure force.
Extruded tapped hole u nuts push the workpiece material downward to create a tapped hole.
The minimum distance from an extruded hole to a bend is three times the material thickness plus the bend radius.
Prepunched or extruded holes on the sheet are threaded through a coordinated rotation of the turret press autoindex station and ram stroke.
Extruded hole to part edge b 3t d 2.
Tapped holes may need to be re tapped after plating to ensure accuracy.
Design for manufacturability sheet metal guidelines bends for the ease of manufacturing multiple bends on the same plane should occur in the same direction.
Avoid large sheet metal parts with small bent flanges.
Performance in extruded holes is slightly higher than in drilled holes.
The tooling produces a full range of threaded holes in.
They are used in thin materials.
Extrusions our commonly used to accept sheet metal screws or permit tapping into a deeper distance than just the material thickness.
Extruded holes very close to the part edge can lead to sheet metal deformation or tearing.