Electro Hardware S545-M04-F16-E Circuit Board Spacer Aluminum

Product Description

The ELECTRO HARDWARE S545-M04-F16-E is a round, female unthreaded circuit board spacer machined from aluminum grade T-3 to the QQ-A-225A Comp 2 fastener standard. It accepts a number 4 screw, has an overall length of 0.75 inches, an outside diameter of 0.25 inches, and an inside diameter of 0.116 inches. This type of spacer is installed between a printed circuit board and a mounting surface or between stacked boards to maintain precise separation, prevent contact shorts, and provide a secure, non-threaded female receptacle for fastening hardware. The uncoated aluminum finish suits applications where weight, corrosion resistance, and electrical conductivity are relevant design factors. Electronics technicians, control board assemblers, and field service technicians working on HVAC control assemblies, electrical panels, and similar equipment install this hardware.

This spacer is suited for use in circuit board mounting applications found in residential and commercial HVAC control boards, electrical enclosures, and industrial electronics assemblies. Its inch-system dimensions and number 4 screw compatibility make it a standard fit for control board mounting configurations commonly encountered in trade service work. The female unthreaded body allows a mating screw to pass through from the board side and seat firmly without requiring a pre-tapped hole in the spacer itself.

Key Features

• Female unthreaded round body accepts number 4 screws
• Overall length of 0.75 inches with a length tolerance of -0.005 to 0.005 inches
• Outside diameter of 0.25 inches and inside diameter of 0.116 inches
• Inside diameter tolerance of 0.000 to 0.010 inches for consistent fit
• Machined from aluminum grade T-3 per QQ-A-225A Comp 2 fastener standard
• Uncoated finish - no plating or coating to affect conductivity or clearance

Compatibility

Designed as an OEM-style replacement or service spacer for circuit board mounting applications requiring a number 4 female unthreaded round spacer with a 0.75-inch overall length and inch-system dimensions.

Installation Notes

Installation is performed by electronics technicians or field service technicians. Always power down and de-energize any control board assembly before removing or installing circuit board hardware. Use the correct number 4 fastener to avoid stripping the unthreaded bore. Handle aluminum spacers carefully to avoid deformation that could alter the inside diameter tolerance and affect proper screw seating.