{"product_id":"electro-hardware-s521-m10-f21-g-circuit-board-spacer","title":"Electro Hardware S521-M10-F21-G Circuit Board Spacer","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe ELECTRO HARDWARE S521-M10-F21-G is a round, female unthreaded circuit board spacer designed to maintain precise standoff distance between a PCB and a mounting surface. Built from Grade 2 steel with a zinc-plated finish per ASTM B633 and QQ-S-633 Type 1, this spacer measures 0.375 inches overall length with a 0.25 inch outside diameter and a 0.141 inch inside diameter. It accepts a No. 6 screw and is sized for applications where consistent board clearance and corrosion resistance are required. Licensed electricians, electronics technicians, and control board assembly professionals install these spacers during PCB mounting and panel assembly work.\u003c\/p\u003e\n\u003cp\u003eThis spacer is suited for use in residential and light commercial control panel assemblies, HVAC control boards, electrical enclosures, and electronic equipment where a No. 6 screw pattern is used. Its compact round body and standardized dimensions make it a practical choice for original-equipment and field-replacement installations requiring a reliable, low-profile standoff with female unthreaded construction.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eFemale unthreaded design accepts No. 6 screws for secure PCB standoff mounting\u003c\/li\u003e\n  \u003cli\u003eGrade 2 steel construction with zinc-plated finish meets ASTM B633 and QQ-S-633 Type 1 standards\u003c\/li\u003e\n  \u003cli\u003eOverall length of 0.375 inches with tight length tolerance of -0.005 to 0.005 inches for precise board clearance\u003c\/li\u003e\n  \u003cli\u003eInside diameter of 0.141 inches with tolerance of 0.000 to 0.010 inches for consistent screw fit\u003c\/li\u003e\n  \u003cli\u003eRound body profile for compact installation in tight panel layouts\u003c\/li\u003e\n  \u003cli\u003eZinc plating provides corrosion resistance in indoor electrical enclosure environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as a standard No. 6 screw female unthreaded round circuit board spacer for PCB standoff applications in electrical control panels and enclosures.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is performed by licensed electricians or qualified electronics assembly technicians. De-energize and lock out the panel or equipment before servicing any control board or enclosure. Insert the spacer between the PCB and mounting surface, aligning the inside diameter with the No. 6 screw path before fastening. Do not overtighten the mating screw, as this spacer is unthreaded and relies on the fastener assembly for clamping force.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Steel, Grade 2\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Zinc-Plated\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBody Shape\u003c\/strong\u003e: Round\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eType\u003c\/strong\u003e: Female Unthreaded\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eScrew Size\u003c\/strong\u003e: No. 6\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 0.375 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLength Tolerance\u003c\/strong\u003e: -0.005 to 0.005 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutside Diameter\u003c\/strong\u003e: 0.25 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInside Diameter\u003c\/strong\u003e: 0.141 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInside Diameter Tolerance\u003c\/strong\u003e: 0.000 to 0.010 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFastener Standards\u003c\/strong\u003e: ASTM B633, QQ-S-633 Type 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSystem of Measurement\u003c\/strong\u003e: Inch\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: ELECTRO HARDWARE\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: S521-M10-F21-G\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ELECTRO HARDWARE","offers":[{"title":"Default Title","offer_id":51743942017330,"sku":"S521-M10-F21-G","price":14.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/e3cc36a356b8db3558f762fd94ce074a.jpg?v=1788851669","url":"https:\/\/voomisupply.com\/products\/electro-hardware-s521-m10-f21-g-circuit-board-spacer","provider":"Voomi Supply","version":"1.0","type":"link"}