Self-Clinching Blind Press Nuts -Series CFB, CFBS
Captive Fastener brand of self clinching blind press nuts provide an excellent design solution for assemblies where there is a desire to protect the contents from foreign matter. The blind press nuts can be installed into panels as thin as .040”/1mm thick. The configuration of the blind press nuts also limit the mating screw’s penetration into the assembly which can prevent any interference within the design. This feature prevents any contact with the electronic circuitry in the design.
The series is comprised of the CFB and CFBS types of blind self clinching press nuts. The CFB series are available in heat treated steel and are generally provided in a zinc clear finish. However, other finishes are available upon request. The CFBS series is available in 300 series stainless steel and are provided in the passivated condition to ASTM A967.
Self-Clinching Blind Press Nut Installation and Design ConsiderationsThe proper installation of each series of blind press nuts requires that the self clinching fastener is harder than the panel into which it will be installed. The CFB series can be installed into steel or aluminum panels with a maximum hardness of HRB 80. The CFBS series can be installed into steel or aluminum panels with a maximum hardness of HRB 70. The blind press nuts can be installed into panels as thin as .040” thick and to be installed properly, they must be inserted in the proper mounting hole in the panel. For example Captive Fastener part number CFB440-1 can be installed into a panel with a minimum sheet thickness of .040” thick. The minimum sheet thickness and proper hole size for each individual fastener is listed in our catalog under Dimensions & Specification.
The proper method to install the fasteners requires that a slow squeezing force be applied, which allows the parent metal to flow around the clinch profile of the fastener. This procedure captivates the fastener in the assembly and they become an integral part of the design. The blind press nuts allow for assembly and later servicing of the assembly if required, with no need to access both sides of the panel. The blind press nuts, along with providing the protection of shielding foreign matter from the design, and the mating screws penetration, they also eliminate the possibility of loose hardware.
The proper installation force and performance values for the blind press nuts are available in our catalog under Installation & Performance Data. We also have an animated installation video here.