Preserve Small Forms
Small forms such as tabs or embosses are often included in sheet metal parts and created before the part is punched or blanked from the sheet metal. Here is a way to perform a blanking operation without deforming or destroying the small forms in the finished part.
Custom-designed tooling with reliefs will allow the pre-made forms to be included in the part, ultimately preventing any damage to occur. The small forms may be placed directly into the sheet metal before the part is blanked out. This allows them to be processed in a punch press rather than in a secondary operation such as a press brake. Including a relief in the tooling allows the forms to enter the relieved area of the tool as the blanking hit is being processed. This prevents them from being damaged or crushed during the blanking operation.
The following recommendations will assist in making good quality blanks:
- Inform your Mate Customer Service representative that tooling will be used for blanking.
- The slug is the final product, so tooling should be ordered with this in mind.
- The die (including clearance) should be the part size. The punch dimensions will then
be calculated based on the die size.
- Reduce the die clearance by 5% to help increase the burnish area and minimize the dimensional difference between the top and bottom of the blanked part. A Mate Applications Specialist can help you with calculations based on material type and thickness.
- Provide Mate with an accurate reference drawing of the part. Critical information will include the height of the forms, as well as length, width and location on the final part.
- Use only sharp punches and dies. This increases the straight or burnished portion of the blank to provide straighter walls on the required parts.
- Punches should be flat-faced, if possible.
- Use straight taper dies.
- Inspect tools frequently for wear. With reduced die clearances, frequent inspection and sharpening are required.
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