Electro Hardware S797-M10-F21-H Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S797-M10-F21-H is a round, female unthreaded circuit board spacer designed to create a fixed standoff distance between a printed circuit board and a mounting surface. Machined from Grade 2 steel with a zinc-plated finish per ASTM B633 and QQ-S-633 Type 1, this spacer provides corrosion resistance suitable for indoor electronic assemblies. It is sized for No. 8 screws, with an overall length of 0.3125 inches, an inside diameter of 0.171 inches, and an outside diameter of 0.3125 inches. Electronics technicians, control board assemblers, and HVAC service technicians who replace or mount circuit boards use this type of hardware during board installation and panel assembly work.

This spacer is suited for use in residential and light commercial electronic control assemblies where a No. 8 fastener is specified. Typical applications include mounting HVAC control boards, relay boards, and general-purpose PCBs to metal or composite panels. Its compact 5/16-inch profile keeps board clearance tight while maintaining consistent standoff height across multiple mounting points. The female unthreaded design accepts a No. 8 screw passed through from the board side, seating the spacer against the substrate.

Key Features

• Female unthreaded round body accepts No. 8 screws for straightforward PCB mounting
• Zinc-plated steel finish per ASTM B633 and QQ-S-633 Type 1 for corrosion resistance
• Grade 2 steel construction provides reliable mechanical strength at a compact size
• Overall length of 0.3125 inches with a length tolerance of -0.005 to 0.005 inches for consistent standoff height
• Inside diameter tolerance of 0.000 to 0.010 inches ensures proper fastener fit
• Round body shape allows uniform seating against board and panel surfaces

Compatibility

Designed as an OEM-style replacement or service spacer for circuit board mounting applications requiring a No. 8 unthreaded female round spacer with a 5/16-inch overall length.

Installation Notes

Installation is performed by electronics technicians or HVAC service professionals during control board replacement or panel assembly. Power down and de-energize any control circuit or panel completely before servicing circuit board hardware. Use a calibrated torque driver appropriate for No. 8 fasteners to avoid over-stressing the unthreaded bore. Verify spacer seating is flush against both the mounting surface and board before applying final fastener load.