b&m-CONTACTFORM®
Thread-forming screw with an additional function for electrical ground bonding
b&m-CONTACTFORM® combines all the properties of a thread-forming screw with those of a ground bonding screw. It eliminates the need for grounding cables when establishing electrical ground connections for cover components during assembly. In addition, it creates a metric thread directly in the mating component, eliminating time-consuming and costly preparation steps such as countersinking, thread cutting and thread cleaning. b&m-CONTACTFORM® provides reliable ground bonding while serving as a tool and fastener in one. The screw can be used for direct fastening in components made of aluminum, steel, magnesium and zinc.
Functional principle
As a thread-forming screw, b&m-CONTACTFORM® creates a metric internal thread even in coated pilot holes. In the process, the coating is selectively displaced, creating direct metal-to-metal contact at the thread crests. Unlike conventional direct fastening solutions with a trilobular thread geometry, b&m-CONTACTFORM® features a circular thread geometry. This enables maximum flank engagement, providing both mechanical advantages and significantly improved electrical conductivity of the connection. The annular cutting edge integrated beneath the screw head additionally removes the coating from the clamped component, thereby establishing reliable electrical contact between the screw and the component.
Benefits
- Electrical ground bonding without the need for additional grounding cables
- Cost-efficient: No preparatory steps are required, as b&m-CONTACTFORM® can be screwed directly into the defined pilot hole
- Suitable for components with pilot holes that have undergone powder coating, painting or cathodic dip coating (CDC); masking the holes is not required
- Easy hole finding thanks to the rounded tip
- Repeat installations possible, with even further improvement in the electrical conductivity of the connection
- High-quality appearance for visible applications
Features
Diameter: M4 – M10
Length: depending on diameter
Property class: F10 (comparable to property class 10.9 according to DIN EN ISO 898)
Head geometry: pan head with collar
Coating: silver zinc nickel; other coatings available upon customer request
