Electro Hardware S561-M10-F21-G Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S561-M10-F21-G is a round, female unthreaded circuit board spacer designed to maintain precise standoff clearance between a printed circuit board and a mounting surface. Machined from Grade 2 steel with a zinc-plated finish, it meets ASTM B633 and QQ-S-633 Type 1 standards for corrosion resistance. The spacer measures 1 inch overall length with an inside diameter of 0.141 inches and an outside diameter of 0.25 inches, sized for a No. 6 screw. Electronics technicians, control board assemblers, and field service techs working on HVAC control panels, electrical enclosures, or similar equipment use this hardware to achieve consistent board-to-chassis spacing.

This spacer is suited for residential and light commercial applications wherever a circuit board requires secure, repeatable standoff mounting. Typical uses include HVAC control board assemblies, electrical panel subassemblies, and industrial enclosure wiring. Its female unthreaded body accepts a No. 6 fastener passed through from the board side, making it straightforward to install in new assemblies or as a replacement in existing control board mounts. The zinc-plated finish provides a level of corrosion protection appropriate for indoor enclosure environments.

Key Features

• Grade 2 steel construction with zinc-plated finish per ASTM B633 and QQ-S-633 Type 1
• Female unthreaded body accepts No. 6 screw for tool-accessible assembly
• 1 inch overall length with tight length tolerance of -0.005 to 0.005 inches
• Inside diameter of 0.141 inches with tolerance of 0.000 to 0.010 inches for consistent fit
• Outside diameter of 0.25 inches in a compact round body profile
• Inch measurement system; suitable for standard North American board mounting configurations

Compatibility

Designed as an OEM-style replacement or new-assembly spacer for circuit board mounting applications requiring a No. 6 screw, 1 inch standoff height, and a 0.25 inch outside diameter round body.

Installation Notes

Installation is performed by electronics technicians or field service professionals working on control board assemblies inside de-energized electrical or HVAC enclosures. Always disconnect and lock out power to the enclosure before handling circuit boards or fasteners. Use a fastener driver appropriate for the No. 6 screw head style in use, and avoid overtightening, which can deform the unthreaded spacer body or crack the circuit board.