{"product_id":"starrett-50991-micrometer-calibration-standard-12-in","title":"Starrett 50991 Micrometer Calibration Standard 12 in","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe STARRETT 50991 is a spherical end micrometer calibration standard designed for verifying and calibrating outside micrometers in precision measurement applications. At 12 inches in length, it provides a long-range reference with accuracy up to 0.000170 inch, making it suitable for high-tolerance inspection work in tool rooms, calibration labs, and production environments. The unit ships calibrated and includes a heat insulating handle to prevent dimensional error caused by thermal expansion during handling. Machinists, metrologists, and quality control technicians rely on this standard to maintain traceable measurement accuracy.\u003c\/p\u003e\n\u003cp\u003eThis calibration standard is used in toolroom and metrology settings where micrometer calibration and verification must meet tight tolerances. The spherical end design ensures consistent contact geometry during measurement checks. It is appropriate for use in both production quality control environments and dedicated calibration labs. The included heat insulating handle is a practical feature for bench technicians who need to hold the standard during extended calibration sessions without introducing thermal drift.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e12-inch overall length provides long-range calibration reference for outside micrometers\u003c\/li\u003e\n  \u003cli\u003eAccuracy up to 0.000170 inch for high-tolerance verification work\u003c\/li\u003e\n  \u003cli\u003eSpherical end geometry ensures repeatable contact during calibration checks\u003c\/li\u003e\n  \u003cli\u003eShips calibrated for immediate use in quality control or metrology applications\u003c\/li\u003e\n  \u003cli\u003eHeat insulating handle minimizes thermal expansion error during handling\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use with outside micrometers requiring a 12-inch calibration reference. Suitable for standard micrometer calibration and verification procedures in toolroom and inspection environments.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eThis standard is handled and used by metrologists, tool room technicians, and calibration professionals rather than installed. Always allow the standard to reach ambient temperature before use to avoid thermal expansion errors. Store in a protective case away from temperature extremes and humidity. Handle only by the heat insulating handle to prevent body heat from affecting dimensional readings.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLength\u003c\/strong\u003e: 12 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAccuracy\u003c\/strong\u003e: 0.000170 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCalibrated\u003c\/strong\u003e: Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIncludes Heat Insulating Handle\u003c\/strong\u003e: Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.625 pounds\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: STARRETT\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 50991\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"STARRETT","offers":[{"title":"Default Title","offer_id":51538664161586,"sku":"50991","price":125.76,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/2faab99ad6a6928b6eac12bbe096f860.jpg?v=1785825463","url":"https:\/\/voomisupply.com\/products\/starrett-50991-micrometer-calibration-standard-12-in","provider":"Voomi Supply","version":"1.0","type":"link"}