{"product_id":"spi-21-904-8-mechanical-hole-micrometer-0-8-1-0-in","title":"Spi 21-904-8 Mechanical Hole Micrometer 0.8-1.0 in","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe SPI 21-904-8 is a mechanical hole micrometer designed for precision internal bore measurement in the range of 0.8000 to 1.0000 inches. It delivers an accuracy of 0.0001 inches (0.002 mm) with a graduation of 0.0002 inches, making it suitable for tight-tolerance machining and inspection work. The micrometer features three self-centering contact points with carbide measuring surfaces and a ratchet stop thimble for consistent, repeatable gauging pressure. Machinists, quality control technicians, and tool and die professionals use this instrument wherever bore diameter verification is required to a high degree of precision.\u003c\/p\u003e\n\u003cp\u003eThe 21-904-8 is appropriate for use in precision manufacturing, machine shop inspection, and tool room environments. It handles internal measurements where standard outside micrometers or bore gauges lack the resolution needed for close-tolerance work. The instrument comes with a setting ring with a 1.0000-inch diameter and one extension rod with a maximum extension rod length of 6.0000 inches, expanding its utility across a range of bore depths up to 3.5500 inches gauge depth. A NIST traceability certification is included, making it suitable for calibrated inspection processes.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eMeasurement range of 0.8000 to 1.0000 inches with 0.0001-inch accuracy\u003c\/li\u003e\n  \u003cli\u003eThree self-centering contact points for repeatable, centered readings\u003c\/li\u003e\n  \u003cli\u003eCarbide measuring surfaces for extended wear resistance\u003c\/li\u003e\n  \u003cli\u003eRatchet stop thimble provides consistent gauging pressure\u003c\/li\u003e\n  \u003cli\u003eChrome finish on micrometer body\u003c\/li\u003e\n  \u003cli\u003eIncludes setting ring and one extension rod; NIST traceability certification included\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style precision measuring instrument for internal bore gauging applications requiring a 0.8000 to 1.0000 inch measurement range in machine shop, tool room, and quality control inspection settings.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eThis instrument is installed and operated by machinists or metrology technicians familiar with precision measuring equipment. Before use, verify calibration with the included setting ring per the manufacturer procedure. Keep measuring surfaces clean and free of chips or debris prior to each measurement. Store in the provided case away from temperature extremes to maintain calibration integrity.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMicrometer Type\u003c\/strong\u003e: Hole\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMeasurement Range\u003c\/strong\u003e: 0.8000 to 1.0000 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAccuracy (Inch)\u003c\/strong\u003e: 0.0001 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAccuracy (mm)\u003c\/strong\u003e: 0.002 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGraduation (Inch)\u003c\/strong\u003e: 0.0002 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Contact Points\u003c\/strong\u003e: 3\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRod Type\u003c\/strong\u003e: Ratchet\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThimble Type\u003c\/strong\u003e: Ratchet Stop\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRod Diameter\u003c\/strong\u003e: 0.9300 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGage Depth\u003c\/strong\u003e: 3.5500 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaximum Extension Rod Length\u003c\/strong\u003e: 6.0000 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSetting Ring Diameter\u003c\/strong\u003e: 1.0000 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Extension Rods Included\u003c\/strong\u003e: 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Setting Rings Included\u003c\/strong\u003e: 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Chrome\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCalibrated\u003c\/strong\u003e: Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTraceability Certification\u003c\/strong\u003e: NIST\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Dimensions\u003c\/strong\u003e: 11.82 inches L x 6.30 inches W x 2.09 inches H\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 4.5 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: SPI\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 21-904-8\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SPIROTHERM","offers":[{"title":"Default Title","offer_id":51693503611186,"sku":"21-904-8","price":625.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/c5523c56506c19057bbce08a88e74445.jpg?v=1788313323","url":"https:\/\/voomisupply.com\/products\/spi-21-904-8-mechanical-hole-micrometer-0-8-1-0-in","provider":"Voomi Supply","version":"1.0","type":"link"}