Vespel® Machining

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Vespel® is a tough but versatile and easy-to-work with composite plastic material, manufactured by DuPont™. Parts and components manufactured from Vespel® deliver consistent high performance in tough physical environments where other materials often fail.

DuPont™ produces Vespel® in a variety of “standard” shapes—rods, tubes, discs, bars, etc.—but in order to achieve the right geometry and dimensions for precision parts, machining is required. Despite its toughness, Vespel® is relatively easy to machine, thanks to the material’s inherent mechanical strength, stiffness, and dimensional stability (even at elevated temperatures caused by machining processes).

Vespel® can be machined using standard metalworking equipment. Via CNC machining, Vespel® can be successfully machined to incredibly tight tolerances once considered too close for plastics. In general, the same techniques used to machine metals can be used in Vespel® machining.

Special Considerations for Vespel® Machining

Sawing: Vespel® can easily be cut with band saws. Sections up to 5” thick can be cut with a standard 10 teeth/inch blade without coolant; finer blades should be used for cutting thinner sections.

Turning: Vespel® can be turned to a fine finish using standard lathe, chucker, or screw machine methods, as long as tool cutting edges are kept sharp. For close tolerances, carbide- or diamond-tipped tools should be used. Turning speeds similar to those used for brass are ideal.

Holding: For holding Vespel®, take precautions to prevent deflection caused by holding fixtures, collects, or chucks—unlike metals, this material may deform if too tightly held. An O.D. or I.D. collet is the most reliable holding method for Vespel®; a six-jaw chuck is recommended to distribute and maintain holding force.

Milling: The same milling operations used on metals can be used on Vespel®. Similar precautions should be taken regarding heat buildup, holding, and tool sharpness. To prevent edge chipping, back up edges with another material or utilize climb milling.

Drilling: Vespel® is more elastic and has a higher coefficient of thermal expansion than metals, and so is more likely to seize during drilling operations. To reduce or eliminate seizing, use standard twist drills, maintain speeds similar to those used for mild steels, and use spade drills to produce good surface finishes with minimal chipping.

Threading: Standard metal-cutting taps can be used to add threads to Vespel® parts and component. However, care must be taken to ensure that the taps do not heat up enough to cause thermal expansion of the material, which can cause the tap to bind.

Grinding: Vespel® can be ground to close tolerances using surface, double disc, or centerless grinders with diamond-dressed wheels. Ideal surface speeds are between 3,000 and 4,000 feet per minute.

Deburring: Burrs can be removed from Vespel® parts via the same methods used on metal parts. Vibratory- or tumble-deburring with abrasive media, detergent, and water is also effective. In some instances, hand deburring may be required.

Vespel® is a registered trademark of DuPont™.

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