BSOS-6440-28 - Blind Threaded Standoffs by PennEngineering ® (PEM ® )

The PEM® BSOS-6440-28 is an extended, high-reliability unified blind threaded standoff engineered to provide deep structural clearance inside thin sheet metal assemblies. Utilizing a field-proven self-clinching design, the fastener inserts into a properly sized round hole with a standard squeezing force, cold-flowing the host metal into its unique retention profile to become a permanent, high-strength fixture with excellent torque-out resistance. This unique hardware component features a #4-40 internal thread housed within a heavier, reinforced #6-32 body dimension, providing enhanced cross-sectional strength and greater stability under load. Because it features a blind-threaded (closed) cavity, the opposite side of the metal sheet remains completely flush and unmarred, maintaining a sleek external cosmetic profile while acting as a reliable barrier against dust, air currents, and environmental contaminants. Manufactured from premium 300 Series Stainless Steel, it provides outstanding mechanical durability and long-lasting corrosion protection, making it an excellent choice for medical devices, datacom/telecom racks, consumer electronics, and automotive enclosures.

Self-Clinching Mechanical Lock: Installs rapidly with a standard pressing action to eliminate loose hardware, tapping, or the thermal stress of welding.

Closed-Bottom Blind Pocket: Guarantees that the reverse surface of the host sheet metal remains entirely flat and smooth while sealing the thread chamber from outside contamination.

Reinforced Body Design: Intelligently combines a standard #4-40 internal thread with a wider #6-32 body profile for superior joint rigidity and torque resistance.

Extended Unified Stacking Height: Supplies a precise 0.875-inch physical standoff gap, optimized for stacking deep multi-layer printed circuit boards or isolating sensitive electronics.