Electro Hardware S553-M10-F21-G Round Board Spacer

Product Description

The ELECTRO HARDWARE S553-M10-F21-G is a round, female unthreaded circuit board spacer designed to provide precise, stable standoff clearance between a PCB 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 delivers corrosion resistance alongside the mechanical strength expected in industrial and commercial electronic assemblies. It measures 0.875 inches overall length with a 0.25 inch outside diameter and a 0.141 inch inside diameter, sized for No. 6 screw applications. Electronics technicians, panel builders, and industrial maintenance personnel use this type of hardware during control board mounting and enclosure assembly work.

This spacer is suited for use in control panel assemblies, HVAC circuit board mounting, electrical enclosures, and similar applications where a fixed standoff clearance is required between a PCB and a chassis or sub-panel. The female unthreaded design accepts a No. 6 screw and holds board position securely without threading into the board itself. It is appropriate for both original equipment assembly and field replacement or repair scenarios where consistent board standoff is critical to proper component clearance and airflow.

Key Features

• Grade 2 steel construction with zinc-plated finish meets ASTM B633 and QQ-S-633 Type 1 standards
• Female unthreaded body accepts No. 6 screws for straightforward board mounting
• Overall length of 0.875 inches provides consistent standoff clearance
• Outside diameter of 0.25 inches and inside diameter of 0.141 inches with tight tolerances (inside diameter tolerance 0.000 to 0.010 inches, length tolerance -0.005 to 0.005 inches)
• Round body shape for uniform load distribution on PCB mounting holes
• Zinc plating provides corrosion resistance in enclosure and panel environments

Compatibility

Designed as an OEM-style replacement or new-installation standoff spacer for circuit board mounting applications requiring a No. 6 screw, female unthreaded, round steel spacer with 0.875 inch overall length.

Installation Notes

Installation is typically performed by electronics technicians, panel builders, or licensed electricians during control board assembly or replacement. Power down and de-energize the control panel or enclosure fully before handling any circuit board hardware. Use appropriately sized No. 6 screws and avoid overtightening, which can crack PCB mounting pads or distort the spacer body. Follow applicable NEC guidelines for control panel assembly and enclosure work.