Metal stamping, a process that employs high-tonnage presses to shape diverse metal materials, often results in burrs. These are rough or raised excess metal areas on the part’s surface or sharp edges. While standard specifications for metal stampings allow a burr margin of 10% of the material thickness, intricate parts might necessitate burr reduction either through an advanced stamping process or post-stamping deburring. Expert metal stampers can offer insights on design, expected burr implications, and optimal deburring techniques.
Why Deburr Metal Stampings?
Materials like steel, stainless steel, copper, and brass often require deburring post-stamping. The Precision Metalforming Association (PMA) Design Guidelines highlight three primary reasons for deburring:
- Ensuring safe handling during manufacturing and usage.
- Preventing abrasive effects, such as damage to insulated wires.
- Enhancing the part’s aesthetic appeal.
Additionally, deburring can remove welding discoloration, foreign contaminants, oxidation, and heat treatment rust. For instance, a part with a sharp edge might pose assembly handling issues or cause abrasion during its operation.
Tommy Polte, VP of Sno-Belt Industries, states that deburring primarily aims to meet edge break or radius edge specifications. The stampings requiring deburring can vary significantly in size.
Deburring Techniques Explained
Common deburring methods for stampings include barrel and vibratory finishing, both of which use abrasive media and a cleaning solution. Electropolishing, albeit pricier, is another option for intricate parts.
- Barrel Deburring: This method involves parts colliding in a rotating tub, making it suitable for robust parts.
- Vibratory Deburring: This technique uses an oscillating channel, ideal for fragile stampings. The choice of media, as Mr. Polte points out, depends on the part’s design and metal type, ranging from BB-sized to two-inch stones.
- Electropolishing: This process immerses parts in a chemical electrolyte bath subjected to an electric current, removing a thin metal layer and contaminants. It’s best for delicate stampings with critical dimensions.
Commonly Deburred Stamped Metal Parts
- Terminals
- Brackets
- Medical device components
- Washers
Seek Expertise from Metal Stamping Engineers
Manufacturers often specify deburring requirements in their RFQs. However, metal stamping engineers can offer invaluable insights on expected burrs based on the part’s crucial dimensions and recommend the most suitable deburring method. They can also suggest approved deburring or electropolishing providers for RFQ estimates.
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