{"product_id":"accupro-88-615-50-ap-retention-knob-cat50-1-8-thread","title":"Accupro 88.615.50.AP Retention Knob CAT50 1-8 Thread","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe ACCUPRO 88.615.50.AP is a CAT50 retention knob designed to secure toolholders in CAT50 spindle tapers on CNC machining centers. It threads into the toolholder drawbar interface using a 1-8 UNC thread and provides the clamping force needed to hold the toolholder firmly during cutting operations. The knob features a high-torque design and a 60-degree angle radius, which distributes clamping load evenly across the spindle interface. Overall length is 3.3524 inches, knob diameter is 0.9055 inches, and the part weighs 0.25 pounds. Machinists and CNC maintenance technicians install and replace these knobs as part of routine toolholder maintenance.\u003c\/p\u003e\n\u003cp\u003eThis retention knob is used in CNC milling and machining center applications wherever a CAT50 spindle interface is present. CAT50 is common in heavy-duty production environments running larger spindle machines. The knob installs directly into the pull stud pocket of the toolholder. Key dimensional references for this application include a knob-to-flange length of 1.7776 inches, a flange thickness of 1.3839 inches, and a neck diameter of 0.6693 inches. Through-coolant is not supported on this part. Style C configuration is used.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eCAT50 taper size for use in heavy-duty CNC machining center spindles\u003c\/li\u003e\n  \u003cli\u003e1-8 UNC thread for direct engagement with toolholder drawbar interface\u003c\/li\u003e\n  \u003cli\u003eHigh-torque design for increased clamping force and toolholder retention\u003c\/li\u003e\n  \u003cli\u003e60-degree angle radius distributes clamping load across the spindle contact surface\u003c\/li\u003e\n  \u003cli\u003eStyle C configuration with 0.6693 inch neck diameter for proper fitment clearance\u003c\/li\u003e\n  \u003cli\u003eNo through-coolant, suitable for dry or external coolant machining setups\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 requiring a 1-8 UNC thread pull stud with Style C geometry.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eRetention knobs are installed and serviced by CNC machinists or machine tool maintenance technicians. Always remove the toolholder from the spindle and ensure the machine is in a safe, powered-down state before replacing a retention knob. Use the manufacturer-specified torque wrench and retention knob socket to achieve proper seating — do not use impact tools. Inspect the toolholder threads for wear or damage before installing a new knob.\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 UNC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStyle\u003c\/strong\u003e: C\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAngle Radius\u003c\/strong\u003e: 60 degrees\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 3.3524 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnob Diameter\u003c\/strong\u003e: 0.9055 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNeck Diameter\u003c\/strong\u003e: 0.6693 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnob to Flange Length\u003c\/strong\u003e: 1.7776 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlange Thickness\u003c\/strong\u003e: 1.3839 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoolant Hole Diameter\u003c\/strong\u003e: 0.3350 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThrough Coolant\u003c\/strong\u003e: No\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHigh Torque\u003c\/strong\u003e: Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.25 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: ACCUPRO\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 88.615.50.AP\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ACCUPRO","offers":[{"title":"Default Title","offer_id":51733405204786,"sku":"88.615.50.AP","price":61.71,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/39d570f3c4c95fb18fc5cd9c99698261.jpg?v=1788755266","url":"https:\/\/voomisupply.com\/products\/accupro-88-615-50-ap-retention-knob-cat50-1-8-thread","provider":"Voomi Supply","version":"1.0","type":"link"}