{"product_id":"accupro-771028-cat40-end-mill-holder-1-2-inch-bore","title":"Accupro 771028 CAT40 End Mill Holder 1\/2 Inch Bore","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe ACCUPRO 771028 is a CAT40 dual contact taper shank end mill holder designed for use in CNC machining centers requiring high-speed, high-precision toolholding. The dual contact interface engages both the taper and the spindle face simultaneously, improving rigidity and reducing runout compared to standard single-contact holders. The holder accepts a 1\/2 inch bore end mill, features a 4 inch projection, and is balanced to 30,000 RPM. Through-coolant capability supports both through-spindle and DIN flange coolant delivery. Runout (TIR) is held to 0.0002 inches, making this holder suitable for finish milling and tight-tolerance work. A licensed machinist or CNC toolroom technician is the typical installer.\u003c\/p\u003e\u003cp\u003eThis holder is suited for horizontal and vertical CNC machining centers equipped with a CAT40 spindle. The 4 inch projection provides clearance for deep-cavity or obstructed workpiece features. The 1-3\/8 inch nose diameter and 1-1\/2 inch clamping depth accommodate standard end mill shank lengths. Through-coolant support makes this holder a practical choice for high-feed operations, hardened materials, or applications where chip evacuation and tool life are critical factors. The 5\/8-11 retention knob thread is standard for CAT40 tooling systems.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eCAT40 dual contact taper shank for increased spindle rigidity and face contact\u003c\/li\u003e\n\u003cli\u003e1\/2 inch bore with 1-1\/2 inch clamping depth for secure end mill retention\u003c\/li\u003e\n\u003cli\u003e4 inch projection for clearance on deep-cavity or complex workpieces\u003c\/li\u003e\n\u003cli\u003eBalanced to 30,000 RPM for high-speed machining applications\u003c\/li\u003e\n\u003cli\u003eThrough-coolant compatible via through-spindle and DIN flange delivery\u003c\/li\u003e\n\u003cli\u003eTIR of 0.0002 inches for tight-tolerance and finish milling work\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or direct-fit toolholder for CAT40 spindle machining centers using a 5\/8-11 retention knob thread.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation should be performed by a qualified CNC toolroom technician or machinist. Power down and lock out the machining center spindle before installing or removing the holder. Use a calibrated torque wrench and the appropriate pull stud when seating the retention knob. Verify runout with a dial test indicator after tool assembly and before running the spindle at speed.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Type\u003c\/strong\u003e: CAT40 Dual Contact Taper\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore Diameter\u003c\/strong\u003e: 1\/2 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNose Diameter\u003c\/strong\u003e: 1-3\/8 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProjection\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClamping Depth\u003c\/strong\u003e: 1-1\/2 inches (38.10 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 6.687 inches (169.84 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTIR\u003c\/strong\u003e: 0.0002 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThrough Coolant\u003c\/strong\u003e: Yes  -  Through-Spindle and DIN Flange\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRetention Knob Thread Size\u003c\/strong\u003e: 5\/8-11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBalanced To\u003c\/strong\u003e: 30,000 RPM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 3.2 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: ACCUPRO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 771028\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ACCUPRO","offers":[{"title":"Default Title","offer_id":52056434442546,"sku":"771028","price":137.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/e171b9230ece530ac8f86a6eeb23db02_7d3f8701-5cad-4ae2-abf8-1acecb96c692.jpg?v=1790038226","url":"https:\/\/voomisupply.com\/products\/accupro-771028-cat40-end-mill-holder-1-2-inch-bore","provider":"Voomi Supply","version":"1.0","type":"link"}