{"product_id":"accupro-er8j400000msc-taper-drill-chuck-arbor-jt4-r8","title":"Accupro ER8J400000MSC Taper Drill Chuck Arbor JT4 R8","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe ACCUPRO ER8J400000MSC is a taper drill chuck arbor designed to connect a Jacobs Taper 4 (JT4) drill chuck to a milling machine or drill press spindle with an R8 shank taper. It serves as the mechanical interface between the chuck and the machine spindle, transmitting rotational force while maintaining precise concentricity. This arbor is used during drilling, boring, and reaming operations where a removable chuck is required. Machinists and tool and die technicians install this component when setting up drill chucks on Bridgeport-style and compatible R8-spindle milling machines. The part weighs 1.32 pounds and ships as a single-unit package.\u003c\/p\u003e\u003cp\u003eThis arbor is suited for machine shop environments requiring reliable chuck-to-spindle connections in light to medium-duty drilling and hole-making operations. The JT4 mount accepts standard Jacobs Taper 4 drill chucks, while the R8 shank seats directly into R8-collet-compatible spindles. It is appropriate for both production and maintenance machining tasks where fast chuck changes and repeatable runout are important.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eJT4 Jacobs Taper mount accepts standard JT4 drill chucks\u003c\/li\u003e\n\u003cli\u003eR8 shank taper seats into R8-spindle milling machines and drill presses\u003c\/li\u003e\n\u003cli\u003eTapered shank and mount design provides self-centering alignment for reduced runout\u003c\/li\u003e\n\u003cli\u003eCompact, single-piece construction with no loose components\u003c\/li\u003e\n\u003cli\u003e1.32-pound weight suited for standard vertical milling spindle loads\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement arbor for milling machines and drill presses equipped with an R8 spindle taper, accepting JT4 Jacobs Taper drill chucks.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation is performed by qualified machinists or tool room technicians. Power down and lock out the machine spindle before seating or removing the arbor. Clean the R8 shank and spindle bore thoroughly before installation to prevent fretting and ensure full taper contact. Do not use the drawbar to force a misaligned taper into the spindle, as this can damage both the arbor and the spindle bore.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount Type\u003c\/strong\u003e: Tapered\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount Taper Size\u003c\/strong\u003e: JT4 (Jacobs Taper 4)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Type\u003c\/strong\u003e: Taper\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Taper Size\u003c\/strong\u003e: R8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 1.32 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity\u003c\/strong\u003e: 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUNSPSC Code\u003c\/strong\u003e: 27112800\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: ACCUPRO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: ER8J400000MSC\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ACCUPRO","offers":[{"title":"Default Title","offer_id":51727394603314,"sku":"ER8J400000MSC","price":75.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/cd2f1c0f31b838ab9b0af79285e6cc85.jpg?v=1788677282","url":"https:\/\/voomisupply.com\/products\/accupro-er8j400000msc-taper-drill-chuck-arbor-jt4-r8","provider":"Voomi Supply","version":"1.0","type":"link"}