Extruding Holes Sheet Metal

Avoid large sheet metal parts with small bent flanges.

Extruding holes sheet metal.

The punch should be polished linearly to a mirrorlike surface finish. Extruded hole to part edge b 3t d 2. Applications include for self tapping sheet metal screws or in thicker material to permit tapping for machine screws. A pre punched hole is required as a one hit pierce and extrude gives poor hole quality and has limited adjustment on the machine.

Tap fix screws for extruded holes in light gauge steel this article provides tap fix hole size recommendations for metals using light gauge punched extruded materials. Center of extruded holes a 5 hole dia 2t extruded hole and bend edge c 3t r d 2. If an extruded hole is too close to the part edge it can lead to deformation or tearing of the metal. The extrusion punch should be made of highly wear resistant tool steel powdered metal pm preferably or solid carbide material.

Relieve the punch after extruding the straight section to allow for lubricant to settle into the negative portion of the punch. Extruding metal is one of the most extreme pressure applications in press working and generates lot of friction and heat. C form height to thickness ratio to determine the minimum form height for sheet metal use the. Extruded holes very close to the part edge can lead to sheet metal deformation or tearing.

Can you clarify what you mean by extruded hole. The diameter of the pre punched hole ultimately determines the height of the extrusion. Extrusions our commonly used to accept sheet metal screws or permit tapping into a deeper distance than just the material thickness. Of all of the factors controlling the success of an extruding operation material type and its mechanical properties are the most influential.

Materials exhibiting good stretch capability and stretch distribution characteristics are best suited for extruding. Both holes and regular extrusions are possible in sheet metal as well as thread features. B for a slot or hole 1 diameter then the minimum distance d 2 5t r see fig. For a hole 1 in diameter the minimum distance d 2t r see fig.

Therefore the minimum distance between the extruded hole to edge if maintained. In low carbon steel sheet metal the minimum radius of a bend should be one half the material thickness or 0 80 mm 0 03 inch whichever is larger. The following illustration shows the extruded hole geometry. Extrusion is the process in which a continuous radial stretch flange is created by expanding a hole.