{"product_id":"mandrino-a-4-griffe-ps4-250","title":"Bernardo 4-jaw lathe chuck PS4-250","description":"\u003cp\u003eThe Bernardo 4-jaw chuck PS4-250 is a professional-grade lathe chuck, weighing 29 kg. Krollit, official Bernardo distributor since 2007.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eChuck size A: 250\u003c\/li\u003e\n\u003cli\u003eB: 85 mm\u003c\/li\u003e\n\u003cli\u003eC: 5 mm\u003c\/li\u003e\n\u003cli\u003ed: 200 mm\u003c\/li\u003e\n\u003cli\u003eE: 76 mm\u003c\/li\u003e\n\u003cli\u003eF: 224 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWho uses the 4-jaw chuck PS4-250 and what for\u003c\/h3\u003e\n\u003cp\u003eMechanical workshops and artisan turners use the 4-jaw chuck PS4-250 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 PS4-250 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 performance: 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 within 3-5 working 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 4-jaw chuck PS4-250 for?\u003c\/h3\u003e\n\u003cp\u003eThe 4-jaw chuck PS4-250 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 for 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 non-symmetrically centered workpieces, consider independent 4-jaw chucks or universal platforms.\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\u003eB\u003c\/td\u003e\n\u003ctd\u003e85 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eC\u003c\/td\u003e\n\u003ctd\u003e5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ed\u003c\/td\u003e\n\u003ctd\u003e200 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE\u003c\/td\u003e\n\u003ctd\u003e76 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eF\u003c\/td\u003e\n\u003ctd\u003e224 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eG\u003c\/td\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eh\u003c\/td\u003e\n\u003ctd\u003e105 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJ\u003c\/td\u003e\n\u003ctd\u003e34 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChuck size A\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\u003e2000 rpm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApprox. weight\u003c\/td\u003e\n\u003ctd\u003e29 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 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 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\u003eWhich workpieces are suitable for a Ø 250 mm diameter?\u003c\/summary\u003e\n\u003cp\u003eSuitable for medium workpieces (max Ø ~220 mm): professional lathes.\u003c\/p\u003e\n\u003cp\u003eThe nominal chuck diameter indicates the maximum body size, not the machinable workpiece size. Clamping capacity depends on jaw opening (typically 60-70% of 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 lathe spindle nose (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 the chuck's 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":50726495551816,"sku":"21-2003F","price":624.61,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/www.krollit.com\/products\/4-jaw-chuck-ps4-250","provider":"Krollit","version":"1.0","type":"link"}