Electro Hardware S1375-M10-F21-K Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S1375-M10-F21-K is a round, female unthreaded circuit board spacer manufactured from Grade 2 steel with a zinc-plated finish. It provides a fixed standoff between a circuit board and a mounting surface, maintaining clearance for airflow and preventing electrical contact. The spacer measures 0.75 inches overall length with a 0.5 inch outside diameter and a 0.257 inch inside diameter, sized to accept a 1/4 inch screw. Electrical and electronics technicians use this fastener hardware during PCB installation and service work in HVAC controls, industrial panels, and similar enclosures.

This spacer is suited for residential and commercial applications wherever printed circuit boards require a secure, fixed standoff from a chassis or DIN rail mounting plate. Typical install scenarios include HVAC control board mounting, electrical enclosure PCB assemblies, and industrial electronics chassis work. The zinc-plated steel construction handles indoor environments where moderate corrosion resistance is needed without the cost of stainless fasteners.

Key Features

• Female unthreaded body accepts a 1/4 inch screw for straightforward PCB mounting
• Overall length of 0.75 inches provides consistent board standoff clearance
• Grade 2 steel construction meets ASTM B633 and QQ-S-633 Type 1 standards
• Zinc-plated finish delivers moderate corrosion resistance for indoor panel use
• Inside diameter tolerance of 0.000 to 0.010 inches ensures consistent screw fit
• Length tolerance of -0.005 to 0.005 inches for precise, repeatable stack height

Compatibility

Designed as an OEM-style replacement or new-installation spacer for circuit board mounting applications requiring a 1/4 inch screw size, 0.75 inch standoff height, and 0.5 inch outside diameter round body in inch-measurement fastener systems.

Installation Notes

Installation is typically performed by licensed electricians or qualified electronics technicians working on control panels and PCB assemblies. Always de-energize the equipment and follow applicable NFPA 70 (NEC) lockout/tagout procedures before servicing any control board or panel. Use the appropriate screwdriver or nut driver for the 1/4 inch screw to avoid damaging the unthreaded spacer body. Do not over-torque the mating fastener, as the unthreaded bore does not provide thread engagement and relies on the screw head and mating hardware for clamping force.