Bernardo 4-jaw chuck DK12-500 is a professional-grade lathe chuck, weighing 142 kg. Krollit, official Bernardo distributor since 2007.
- D - Chuck size: 500
- D1: 420 mm
- D2: 458 mm
- D3: 210 mm
- h: 205 mm
- H1: 115 mm
Who uses the DK12-500 4-jaw chuck and for what purpose
Machine shops and artisan turners use the DK12-500 4-jaw chuck as a clamping accessory on metal lathes, ensuring secure clamping and centering of the workpiece during turning, drilling, and grooving operations.
Its place in the Bernardo range
The Bernardo 4-jaw chuck DK12-500 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.
Krollit logistics and support
Shipping 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.
Who is the DK12-500 4-jaw chuck for?
The DK12-500 4-jaw chuck is recommended for the following professional profiles:
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Machine shops and artisan turners: secure clamping of round or hexagonal workpieces on metal lathes during turning, drilling, and grooving operations.
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Users with a compatible flange Bernardo lathe: original replacement or upgrade for Bernardo lathes (Profi, Hobby, etc.) with A2 mount compliant with DIN 55029.
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Irregular or non-round workpieces: for non-symmetrically centered workpieces, consider independent 4-jaw chucks or universal faceplates.
Technical specifications
| D1 |
420 mm |
| D2 |
458 mm |
| D3 |
210 mm |
| h |
205 mm |
| H1 |
115 mm |
| h |
6 mm |
| Mounting screws |
6 x M16 |
| D - Chuck size |
500 |
| Max. speed |
800 rpm |
| Approx. weight |
142 kg |
Frequently asked questions
When to use a 4-jaw chuck?
Self-centering 4-jaw chucks are for square and 4-8 sided workpieces. The jaws move together with a single key.
A self-centering 4-jaw chuck (not independent jaw) clamps square or octagonal workpieces symmetrically. For off-center (eccentric, asymmetric) clamping, independent jaw chucks are needed.
What material is the chuck body made of?
The material is indicated in the title: steel (PO series) for maximum precision, cast iron (DK/PS series) for standard use.
The choice depends on the intensity of use and the required tolerance: steel for production and precision, cast iron for general use.
What workpieces is the Ø 500 mm diameter suitable for?
Suitable for large workpieces (max. Ø ~600 mm): heavy industrial lathes.
The nominal diameter of the chuck indicates the maximum size of the body, not the machinable workpiece. The clamping capacity depends on the jaw opening (typically 60-70% of the nominal Ø).
How do I check compatibility with my lathe?
Check the mounting type of the lathe spindle nose (Camlock D3-D15, or threaded mount M-) and the corresponding diameter.
On 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.
How is chuck accuracy maintained?
Regular cleaning of the scroll mechanism, periodic lubrication with specific chuck grease, concentricity check every 6 months with a dial indicator.
A 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.
