{"product_id":"mandrino-a-3-ganasce-in-acciaio-po3-250-d8","title":"Bernardo 3-jaw steel lathe chuck PO3-250\/D8","description":"\u003cp\u003eThe Bernardo 3-jaw steel chuck PO3-250\/D8 is a lathe chuck for professional use, with a diameter of 250 mm and a weight of 32 kg. Krollit, official Bernardo distributor since 2007.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eChuck size: 250\/D8\u003c\/li\u003e\n\u003cli\u003eDiameter: 250 mm\u003c\/li\u003e\n\u003cli\u003eTaper: 8\u003c\/li\u003e\n\u003cli\u003eB: 89 mm\u003c\/li\u003e\n\u003cli\u003eD (max.): 139,734 mm\u003c\/li\u003e\n\u003cli\u003eE: 76 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWho uses the 3-jaw steel chuck PO3-250\/D8 and for what\u003c\/h3\u003e\n\u003cp\u003eMechanical workshops and artisan turners use the 3-jaw steel chuck PO3-250\/D8 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 3-jaw steel chuck PO3-250\/D8 is part of the Bernardo lathe chuck range, 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 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 is the 3-jaw steel chuck PO3-250\/D8 for?\u003c\/h3\u003e\n\u003cp\u003eThe 3-jaw steel chuck PO3-250\/D8 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 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 attachment compliant with DIN 55029.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIrregular or non-round workpieces\u003c\/strong\u003e: For non-symmetrically centered workpieces, consider 4-jaw independent 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\u003eDiameter\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\u003eB\u003c\/td\u003e\n\u003ctd\u003e89 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD (max.)\u003c\/td\u003e\n\u003ctd\u003e139,734 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\u003eF1\u003c\/td\u003e\n\u003ctd\u003e171,4 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCam-lock studs\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003c\/tr\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\u003eMax. speed\u003c\/td\u003e\n\u003ctd\u003e3500 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 3-jaw chuck?\u003c\/summary\u003e\n\u003cp\u003eSelf-centering 3-jaw chucks are for cylindrical, hexagonal, and 3-6-9-12 sided workpieces. The jaws move together with a single key (self-centering).\u003c\/p\u003e\n\u003cp\u003eIt is the most common chuck on lathes: quick clamping of symmetrical workpieces, typical concentricity precision of 0.03-0.1 mm depending on the body material (steel = better precision, cast iron = standard).\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhy a steel chuck compared to cast iron?\u003c\/summary\u003e\n\u003cp\u003eSteel chucks (PO series) offer superior concentricity precision (0.01-0.03 mm) and greater wear resistance in intensive machining.\u003c\/p\u003e\n\u003cp\u003eGround steel: higher weight, but smaller dimensions for the same nominal diameter. Suitable for series production and precision turning on treated steels or hard alloys.\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 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 mounting 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 mounting of your lathe before purchase: the interface flange must exactly match the code. Camlock = quick closing 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 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":50726449938760,"sku":"21-1045F","price":1276.76,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/www.krollit.com\/products\/mandrino-a-3-ganasce-in-acciaio-po3-250-d8","provider":"Krollit","version":"1.0","type":"link"}