The Bernardo DK12-400 4-jaw chuck is a lathe chuck for professional use, weighing 80 kg. Krollit, official Bernardo distributor since 2007.
- D - Chuck size: 400
- D1: 330 mm
- D2: 362 mm
- D3: 130 mm
- h: 173.5 mm
- H1: 100 mm
Who uses the DK12-400 4-jaw chuck and what for
Mechanical workshops and artisan turners use the DK12-400 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 DK12-400 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.
Krollit logistics and support
Shipping in 3-5 business days from Krollit warehouse for spare parts and accessories. Italian-speaking customer support available for technical documentation and compatibility verification with the reference machine. Krollit has been an official distributor since 2007.
Who is the DK12-400 4-jaw chuck for
The DK12-400 4-jaw chuck is recommended for the following professional profiles:
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Mechanical workshops and artisan turners: secure clamping of round or hexagonal workpieces on metal lathes for turning, drilling, and grooving operations.
-
Users with a Bernardo lathe with a compatible flange: original replacement or upgrade for Bernardo range lathes (profi, hobby, etc.) with A2 spindle nose conforming to DIN 55029.
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Irregular or non-round shaped workpieces: for asymmetrically off-center workpieces, consider independent 4-jaw chucks or universal faceplates.
Technical specifications
| D1 |
330 mm |
| D2 |
362 mm |
| D3 |
130 mm |
| h |
173.5 mm |
| H1 |
100 mm |
| h |
6 mm |
| Mounting screws |
6 x M16 |
| D - Chuck size |
400 |
| Max. speed |
1000 rpm |
| Approx. weight |
80 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.
The 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 400 mm diameter suitable for?
Suitable for medium-large workpieces (max Ø ~360 mm): industrial lathes.
The nominal diameter of the chuck indicates the maximum size of the body, not that of 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 type of spindle nose mounting on the lathe (Camlock D3-D15, or threaded M-attachment) and the corresponding diameter.
On modern lathes, Camlock mounting is the most common. Older lathes may have threaded (M-) or flanged attachments. The lathe's technical documentation indicates the exact type.
How do I maintain the precision of the chuck?
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 rectified bar and measuring with a dial indicator: acceptable tolerance 0.03-0.1 mm depending on the model.
