{"product_id":"parlec-50trk-390-p-cat50-retention-knob-1-8-thread","title":"Parlec 50TRK-390-P CAT50 Retention Knob 1-8 Thread","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe PARLEC 50TRK-390-P is a CAT50 retention knob designed for securing toolholders in CAT50 spindle interfaces on CNC machining centers. It features a 1-8 thread size, a 1.14-inch knob diameter, and a 45-degree angle radius conforming to Style A geometry. Through-coolant capability is built in, with a 0.39-inch coolant hole diameter that allows direct coolant delivery through the spindle. At 2.3 inches overall length and 0.405 pounds, this knob provides the clamping interface between the drawbar and the toolholder, making secure tool retention and coolant flow possible in demanding production environments. Installation is handled by CNC machine operators and toolroom technicians.\u003c\/p\u003e\n\u003cp\u003eThis retention knob fits CAT50 toolholders used in vertical and horizontal machining centers with CAT50 spindle tapers. The 1-8 thread engages the toolholder pull stud thread directly. The 0.82-inch neck diameter and 1.026-inch pilot diameter are dimensioned to the CAT50 standard. The through-coolant design supports high-pressure coolant systems, making this knob suitable for applications where flood coolant alone is insufficient and directed coolant-through-tool delivery is required.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eCAT50 taper size for use in standard CAT50 spindle interfaces\u003c\/li\u003e\n  \u003cli\u003e1-8 thread size for direct engagement with CAT50 toolholder pull stud threads\u003c\/li\u003e\n  \u003cli\u003eThrough-coolant capable with a 0.39-inch coolant hole diameter\u003c\/li\u003e\n  \u003cli\u003e45-degree angle radius, Style A geometry\u003c\/li\u003e\n  \u003cli\u003e1.14-inch knob diameter with 0.82-inch neck diameter and 1.026-inch pilot diameter\u003c\/li\u003e\n  \u003cli\u003e2.3-inch overall length with 1.0-inch knob-to-flange length and 0.2-inch flange thickness\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement retention knob for CAT50 toolholders with a 1-8 pull stud thread in machining center spindles requiring Style A retention knob geometry.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eRetention knobs are installed and serviced by CNC machine operators or toolroom technicians. Always ensure the spindle drawbar is fully released and machine power is locked out before removing or installing a retention knob. Use a retention knob wrench appropriate for the CAT50 knob diameter to achieve proper torque without damaging the threads or knob geometry. Inspect the coolant hole and toolholder bore for debris before assembly to maintain unobstructed coolant flow.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTaper Size\u003c\/strong\u003e: CAT50\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 1-8\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStyle\u003c\/strong\u003e: A\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAngle Radius\u003c\/strong\u003e: 45 degrees\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2.3 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnob Diameter\u003c\/strong\u003e: 1.14 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNeck Diameter\u003c\/strong\u003e: 0.82 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePilot Diameter\u003c\/strong\u003e: 1.026 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnob to Flange Length\u003c\/strong\u003e: 1.0 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlange Thickness\u003c\/strong\u003e: 0.2 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoolant Hole Diameter\u003c\/strong\u003e: 0.39 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThrough Coolant\u003c\/strong\u003e: Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.405 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: PARLEC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 50TRK-390-P\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"PARLEC","offers":[{"title":"Default Title","offer_id":52024156684594,"sku":"50TRK-390-P","price":64.86,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/cbbd15d3be0cee911329466d05b92028.jpg?v=1790014586","url":"https:\/\/voomisupply.com\/products\/parlec-50trk-390-p-cat50-retention-knob-1-8-thread","provider":"Voomi Supply","version":"1.0","type":"link"}