Electro Hardware S537-M10-F21-H Round Board Spacer No. 8

Product Description

The ELECTRO HARDWARE S537-M10-F21-H is a round, female unthreaded circuit board spacer machined from Grade 2 steel with a zinc-plated finish. It measures 0.625 inches in overall length, 0.25 inches in outside diameter, and 0.171 inches in inside diameter, sized to accept a No. 8 screw. The zinc plating meets ASTM B633 and QQ-S-633 Type 1 finish standards, providing corrosion resistance in typical indoor enclosure environments. This spacer is installed by electronics assemblers, field service technicians, and control board repair professionals who need a reliable standoff to maintain clearance between a PCB and a mounting surface.

This spacer is used in control board mounting applications across HVAC, electrical, and general industrial assemblies. It functions as a standoff that holds a circuit board at a fixed distance from a panel or chassis, preventing short circuits and allowing airflow beneath the board. The female unthreaded body accepts a No. 8 fastener passed through from below, making it suitable for single-sided fastening layouts in residential and light commercial equipment enclosures.

Key Features

• Grade 2 steel construction meets ASTM B633 and QQ-S-633 Type 1 finish specifications
• Zinc-plated finish provides corrosion resistance for indoor enclosure use
• Female unthreaded body accepts No. 8 screw for straightforward single-fastener installation
• 0.625 inch overall length with tight length tolerance of -0.005 to 0.005 inches
• 0.171 inch inside diameter with inside diameter tolerance of 0.000 to 0.010 inches
• Round body shape for consistent seating against PCB and mounting surface

Compatibility

Designed as an OEM-style replacement or service spacer for circuit board mounting applications requiring a No. 8 screw, 0.625 inch standoff height, and a 0.25 inch outside diameter round body in steel construction.

Installation Notes

Circuit board spacers of this type are installed by licensed technicians or trained electronics assemblers during control board service or replacement. Power down the equipment and discharge any capacitors before accessing the control board. Use appropriately sized No. 8 fasteners and avoid overtightening, which can crack the PCB or deform the spacer. Follow applicable equipment manufacturer torque guidelines and local electrical codes when servicing control assemblies.