Electro Hardware S537M17F16H Round Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S537M17F16H is a round, female unthreaded circuit board spacer designed to maintain precise separation between a printed circuit board and a mounting surface or adjacent board. Manufactured from Nylon Grade 101 to MIL-P-17091B, this spacer measures 0.625 inches overall length with a 0.25 inches outside diameter and a 0.171 inches inside diameter sized for a No. 8 screw. The uncoated finish keeps the profile clean and interference-free in tight PCB assemblies. It is installed by electronics technicians, HVAC controls technicians, and electrical tradespeople working on control board mounting applications.

This spacer is suited for use in residential and light commercial control board assemblies, panel-mount PCB installations, and equipment where a standardized standoff solution is needed for No. 8 fastener patterns. It applies wherever a female unthreaded round spacer conforming to MIL-P-17091B dimensional and material standards is specified. The nylon construction provides electrical isolation between the board and the mounting chassis, making it appropriate for both high-volume OEM assembly and field repair work.

Key Features

• Nylon Grade 101 construction provides electrical insulation between PCB and chassis
• Conforms to MIL-P-17091B fastener standard for consistent dimensional compliance
• Female unthreaded body accepts a No. 8 screw with 0.171 inches inside diameter
• Overall length of 0.625 inches with tight length tolerance of -0.005 to 0.005 inches
• Inside diameter tolerance of 0.000 to 0.010 inches for controlled fit on No. 8 hardware
• Uncoated bright finish — no added material to alter clearance or dielectric properties

Compatibility

Designed as an OEM-style replacement or new-installation spacer for circuit board mounting applications requiring a round, female unthreaded nylon standoff sized for No. 8 screw hardware per MIL-P-17091B.

Installation Notes

Installation is performed by electronics technicians or controls electricians during PCB mounting or replacement procedures. De-energize all control circuits and discharge any stored capacitance before handling circuit boards or fasteners. Standard hand tools and the correct No. 8 fastener are all that is required. Do not overtighten fasteners through nylon spacers, as the unthreaded bore can deform under excessive clamp load.