{"product_id":"parlec-4004trkc-retention-knob-bt40-m16-x-2-00-through-coolant","title":"Parlec 4004TRKC Retention Knob BT40 M16 X 2.00 Through Coolant","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe PARLEC 4004TRKC is a BT40 retention knob designed to secure toolholders in BT40 spindle interfaces on CNC machining centers. It threads into the toolholder drawbar at M16 x 2.00 and seats against the spindle with a 60-degree angle radius for consistent clamping force and accurate tool seating. The knob features a through-coolant passage with a 0.197-inch coolant hole diameter, allowing coolant delivery directly through the spindle when the machine and toolholder support it. At 2.36 inches overall length and 0.145 pounds, it is a direct-fit hardware component installed by CNC machinists and toolroom technicians.\u003c\/p\u003e\u003cp\u003eThis retention knob is used in BT40 toolholder assemblies on vertical and horizontal machining centers equipped with BT40 spindles. The Style C designation refers to the knob geometry, which suits standard BT40 toolholders requiring M16 x 2.00 thread engagement. The through-coolant design makes it well-suited for applications where internal coolant delivery is required, such as drilling, reaming, and high-speed milling operations where flood coolant alone is insufficient.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eBT40 taper interface with M16 x 2.00 thread for standard BT40 toolholder compatibility\u003c\/li\u003e\n\u003cli\u003e60-degree angle radius for consistent and repeatable spindle clamping engagement\u003c\/li\u003e\n\u003cli\u003eThrough-coolant capable with 0.197-inch coolant hole diameter\u003c\/li\u003e\n\u003cli\u003eStyle C geometry with 0.669-inch pilot diameter for precise toolholder alignment\u003c\/li\u003e\n\u003cli\u003eCompact 0.588-inch knob diameter and 2.36-inch overall length for direct replacement fitment\u003c\/li\u003e\n\u003cli\u003eLightweight at 0.145 pounds, minimizing added mass in high-speed spindle assemblies\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned for use with BT40 toolholders requiring an M16 x 2.00 retention knob thread. Specific toolholder compatibility should be confirmed against the toolholder manufacturer's retention knob specification before installation.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eRetention knobs are installed by machinists or toolroom technicians during toolholder assembly. The spindle must be fully de-energized and the machine placed in a safe state before any toolholder or retention knob service. Use the correct spanner or retention knob wrench to achieve proper seating torque per the toolholder manufacturer's specification. Do not overtighten, as this can distort the toolholder taper or damage the drawbar thread.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTaper Size\u003c\/strong\u003e: BT40\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: M16 x 2.00\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStyle\u003c\/strong\u003e: C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2.36 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKnob Diameter\u003c\/strong\u003e: 0.588 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKnob to Flange Length\u003c\/strong\u003e: 1.376 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlange Thickness\u003c\/strong\u003e: 0.24 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNeck Diameter\u003c\/strong\u003e: 0.393 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePilot Diameter\u003c\/strong\u003e: 0.669 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAngle Radius\u003c\/strong\u003e: 60 degrees\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThrough Coolant\u003c\/strong\u003e: Yes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoolant Hole Diameter\u003c\/strong\u003e: 0.197 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.145 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\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: 4004TRKC\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"PARLEC","offers":[{"title":"Default Title","offer_id":51972174217522,"sku":"4004TRKC","price":66.61,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/66abed4323680b651785511b31959fb1.jpg?v=1789963691","url":"https:\/\/voomisupply.com\/products\/parlec-4004trkc-retention-knob-bt40-m16-x-2-00-through-coolant","provider":"Voomi Supply","version":"1.0","type":"link"}