Electro Hardware S593-M10-F21-H Round Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S593-M10-F21-H is a round, female unthreaded circuit board spacer designed to maintain precise standoff distances between a printed circuit board and a mounting surface. Machined from Grade 2 steel with a zinc-plated finish meeting ASTM B633 and QQ-S-633 Type 1 specifications, this spacer provides corrosion resistance in light-duty electronic assemblies. It accepts a No. 8 screw, measures 1.5 inches in overall length, and features an inside diameter of 0.171 inches with a length tolerance of -0.005 to 0.005 inches. Electronics assembly technicians and control board service technicians typically use these spacers during PCB mounting and replacement work.

This spacer is suited for residential and commercial electronic control assemblies where a round steel standoff is required to separate and secure circuit boards from chassis or enclosure surfaces. Common applications include HVAC control board installations, electrical panel sub-assemblies, and industrial electronic enclosures where No. 8 fasteners are the standard mounting hardware. The female unthreaded body allows a screw to pass through or seat against the spacer without thread engagement at the spacer itself.

Key Features

• Female unthreaded round body accepts No. 8 screw for secure PCB standoff mounting
• Grade 2 steel construction with zinc-plated finish per ASTM B633 and QQ-S-633 Type 1
• Overall length of 1.5 inches with a tight length tolerance of -0.005 to 0.005 inches
• Inside diameter of 0.171 inches with a tolerance of 0.000 to 0.010 inches
• Outside diameter of 0.25 inches for compact board-to-board or board-to-chassis spacing
• Inch measurement system; sold individually with a minimum order quantity of 1

Compatibility

Designed as a standard-dimension replacement or new-installation spacer for electronic assemblies requiring a No. 8 screw, round, female unthreaded steel standoff with a 1.5-inch overall length and 0.25-inch outside diameter.

Installation Notes

Installation is typically performed by electronics assembly technicians or control board service personnel. Power down and de-energize all equipment before removing or installing circuit board hardware. Use appropriately sized drivers and avoid overtightening fasteners through the unthreaded bore, as the spacer is not designed to carry thread load. Follow applicable equipment manufacturer guidelines and NEC requirements when servicing electrical enclosures.