{"product_id":"mandrino-a-4-griffe-dk12-250","title":"Bernardo Lathe Chuck 4-Jaw DK12-250","description":"\u003cp\u003eThe Bernardo 4-jaw chuck DK12-250 is a lathe chuck for professional use, weighing 28.7 kg. Krollit, official Bernardo distributor since 2007.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eD - Chuck size: 250\u003c\/li\u003e\n\u003cli\u003eD1: 200 mm\u003c\/li\u003e\n\u003cli\u003eD2: 224 mm\u003c\/li\u003e\n\u003cli\u003eD3: 80 mm\u003c\/li\u003e\n\u003cli\u003eh: 120 mm\u003c\/li\u003e\n\u003cli\u003eH1: 80 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWho uses the 4-jaw chuck DK12-250 and for what\u003c\/h3\u003e\n\u003cp\u003eMechanical workshops and artisan turners use the 4-jaw chuck DK12-250 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 4-jaw chuck DK12-250 is part of the Bernardo lathe chuck range, 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 selection assistance.\u003c\/p\u003e\n\u003ch3\u003eKrollit logistics and support\u003c\/h3\u003e\n\u003cp\u003eShipping 3-5 business days from Krollit warehouse for spare parts and accessories. Customer support in Italian 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 the 4-jaw chuck DK12-250 is for\u003c\/h3\u003e\n\u003cp\u003eThe 4-jaw chuck DK12-250 is recommended for the following professional profiles:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical workshops and artisan turners\u003c\/strong\u003e: secure clamping of round or hexagonal workpieces on metal lathes during turning, drilling, and grooving operations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUsers with a compatible flanged Bernardo lathe\u003c\/strong\u003e: original replacement or upgrade for Bernardo range lathes (Profi, Hobby, etc.) with A2 spindle nose according to DIN 55029.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIrregular or non-round shaped workpieces\u003c\/strong\u003e: for non-symmetrically centered 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\u003eD1\u003c\/td\u003e\n\u003ctd\u003e200 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD2\u003c\/td\u003e\n\u003ctd\u003e224 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\u003eh\u003c\/td\u003e\n\u003ctd\u003e120 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH1\u003c\/td\u003e\n\u003ctd\u003e80 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eh\u003c\/td\u003e\n\u003ctd\u003e5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting screws\u003c\/td\u003e\n\u003ctd\u003e6 x M12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD - Chuck size\u003c\/td\u003e\n\u003ctd\u003e250\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\u003eWeight approx.\u003c\/td\u003e\n\u003ctd\u003e28.7 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 jaw) clamps square or octagonal workpieces symmetrically. For off-center (eccentric, asymmetrical) 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 usage intensity 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 body size, not the size 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\u003eHow do I check compatibility with my lathe?\u003c\/summary\u003e\n\u003cp\u003eCheck the type of spindle nose mounting (Camlock D3-D15, or threaded M-mount) and the corresponding diameter.\u003c\/p\u003e\n\u003cp\u003eOn modern lathes, Camlock mounting is the most common. On older lathes, there may be a threaded (M-) or flanged mount. The lathe's technical documentation indicates the exact type.\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 ground 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":50726475858248,"sku":"21-0805","price":513.46,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/www.krollit.com\/products\/4-jaw-chuck-dk12-250","provider":"Krollit","version":"1.0","type":"link"}