Electro Hardware S505-M10-F21-H Round Pcb Spacer No. 8

Product Description

The ELECTRO HARDWARE S505-M10-F21-H is a round, female unthreaded circuit board spacer designed to maintain precise spacing between a printed circuit board and a mounting surface. Manufactured from Grade 2 steel with a zinc-plated finish per ASTM B633 and QQ-S-633 Type 1, this spacer delivers corrosion resistance and dimensional consistency in control board assemblies. It accepts a No. 8 screw, measures 0.125 inches overall length, has an inside diameter of 0.171 inches, and an outside diameter of 0.25 inches. Inside diameter tolerance runs 0.000 to 0.010 inches and length tolerance is -0.005 to 0.005 inches. Electronics technicians, HVAC controls installers, and electrical panel assemblers use this spacer during board-level service and assembly work.

This spacer is suited for residential and light commercial control board installations where a No. 8 fastener is used to mount a circuit board to a chassis or sub-panel. Common applications include furnace control board replacement, air handler electrical compartments, and general electrical enclosure PCB mounting where a compact, low-profile standoff is required. Its small OAL of 0.125 inches makes it appropriate for tight clearance situations where thicker spacers would create interference.

Key Features

• Female unthreaded round body accepts No. 8 screws for secure board mounting
• Zinc-plated steel finish meets ASTM B633 and QQ-S-633 Type 1 for corrosion resistance
• Grade 2 steel construction provides consistent dimensional stability
• 0.125 inches OAL suits tight-clearance PCB mounting applications
• Inside diameter tolerance of 0.000 to 0.010 inches ensures reliable fastener fit
• Length tolerance of -0.005 to 0.005 inches supports repeatable stack height

Compatibility

Designed as an OEM-style replacement or service spacer for circuit board assemblies using No. 8 screw fasteners with a 0.25 inch outside diameter mounting footprint.

Installation Notes

Installation is performed by electronics technicians or licensed HVAC and electrical service professionals. De-energize all power to the control board or electrical enclosure before removing or installing circuit board hardware. Use appropriate non-magnetic or ESD-safe tools when handling circuit boards to avoid component damage. Verify spacer stack height against the original board mounting specification before final fastener torque.