{"product_id":"mandrino-a-4-griffe-dk12-250-d8","title":"Bernardo 4-jaw lathe chuck DK12-250\/D8","description":"\u003cp\u003eThe Bernardo DK12-250\/D8 4-jaw chuck is a professional lathe chuck, with a diameter of 250 mm and a weight of 32 kg. Krollit has been an official Bernardo distributor since 2007.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eChuck size: 250\/D8\u003c\/li\u003e\n\u003cli\u003eD - Diameter: 250 mm\u003c\/li\u003e\n\u003cli\u003eTaper: 8\u003c\/li\u003e\n\u003cli\u003eD1 (max.): 139.734 mm\u003c\/li\u003e\n\u003cli\u003eD2: 171.4 mm\u003c\/li\u003e\n\u003cli\u003eD3: 80 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWho uses the DK12-250\/D8 4-jaw chuck and what for?\u003c\/h3\u003e\n\u003cp\u003eMachine shops and artisan turners use the DK12-250\/D8 4-jaw chuck as a clamping accessory on metal lathes, ensuring secure clamping and centering of the workpiece during turning, drilling, and grooving operations.\u003c\/p\u003e\n\u003ch3\u003eIts place in the Bernardo range\u003c\/h3\u003e\n\u003cp\u003eThe Bernardo DK12-250\/D8 4-jaw chuck is part of Bernardo's range of lathe chucks, distributed in Italy by Krollit since 2007. The Bernardo range includes models of various categories and performances: to choose the right machine for your use case, you can consult the Bernardo catalog on Krollit or contact customer support for assistance with selection.\u003c\/p\u003e\n\u003ch3\u003eKrollit logistics and support\u003c\/h3\u003e\n\u003cp\u003eShipping within 3-5 business days from Krollit warehouse for spare parts and accessories. Italian customer support available for technical documentation and compatibility verification with the reference machine. Krollit has been an official distributor since 2007.\u003c\/p\u003e\n\u003ch3\u003eWho is the DK12-250\/D8 4-jaw chuck for?\u003c\/h3\u003e\n\u003cp\u003eThe dk12-250\/d8 4-jaw chuck is recommended for the following professional profiles:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMachine shops and artisan turners\u003c\/strong\u003e: secure clamping of round or hexagonal workpieces on a metal lathe during turning, drilling, and grooving operations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUsers with a Bernardo lathe with a compatible flange\u003c\/strong\u003e: original replacement or upgrade for Bernardo range lathes (profi, hobby, etc.) with A2 mount conforming to DIN 55029.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIrregular or non-round workpieces\u003c\/strong\u003e: for asymmetrically uncentered workpieces, consider independent 4-jaw chucks or universal faceplates.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eChuck size\u003c\/td\u003e\n\u003ctd\u003e250\/D8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD - Diameter\u003c\/td\u003e\n\u003ctd\u003e250 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTaper\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD1 (max.)\u003c\/td\u003e\n\u003ctd\u003e139.734 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD2\u003c\/td\u003e\n\u003ctd\u003e171.4 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD3\u003c\/td\u003e\n\u003ctd\u003e80 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH1\u003c\/td\u003e\n\u003ctd\u003e96.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax. speed\u003c\/td\u003e\n\u003ctd\u003e1600 rpm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApprox. weight\u003c\/td\u003e\n\u003ctd\u003e32 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhen to use a 4-jaw chuck?\u003c\/summary\u003e\n\u003cp\u003eSelf-centering 4-jaw chucks are for square and 4-8 sided workpieces. The jaws move together with a single key.\u003c\/p\u003e\n\u003cp\u003eThe self-centering 4-jaw chuck (not independent jaws) clamps square or octagonal workpieces symmetrically. For eccentric (asymmetric) clamping, independent jaw chucks are needed.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat material is the chuck body made of?\u003c\/summary\u003e\n\u003cp\u003eThe material is indicated in the title: steel (PO series) for maximum precision, cast iron (DK\/PS series) for standard use.\u003c\/p\u003e\n\u003cp\u003eThe choice depends on the intensity of use and required tolerance: steel for production and precision, cast iron for general use.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat workpieces is the Ø 250 mm diameter suitable for?\u003c\/summary\u003e\n\u003cp\u003eSuitable for medium workpieces (max Ø ~220 mm): professional lathes.\u003c\/p\u003e\n\u003cp\u003eThe nominal diameter of the chuck indicates the maximum size of the body, not that of the workable workpiece. The clamping capacity depends on the jaw opening (typically 60-70% of the nominal Ø).\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat does the D8 taper indicate?\u003c\/summary\u003e\n\u003cp\u003eThe D8 code (Camlock according to DIN 55029) identifies the size of the lathe spindle nose: D3-D5 for small lathes, D6-D8 for medium, D11-D15 for industrial.\u003c\/p\u003e\n\u003cp\u003eCheck the taper of your lathe before purchasing: the interface flange must exactly match the code. Camlock = quick-release with cams, disassembly in 30 seconds without tools.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow is chuck precision maintained?\u003c\/summary\u003e\n\u003cp\u003eRegular cleaning of the spiral mechanism, periodic lubrication with specific chuck grease, concentricity check every 6 months with a dial indicator.\u003c\/p\u003e\n\u003cp\u003eA jaw that moves with difficulty indicates chips or rust in the mechanism: disassemble, clean, and grease. Concentricity is checked by mounting a rectified bar and measuring with a dial indicator: acceptable tolerance 0.03-0.1 mm depending on the model.\u003c\/p\u003e\n\u003c\/details\u003e","brand":"Bernardo","offers":[{"title":"Default Title","offer_id":50726476710216,"sku":"21-0837","price":659.04,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/www.krollit.com\/products\/4-jaw-chuck-dk12-250-d8","provider":"Krollit","version":"1.0","type":"link"}