The Bernardo 3-jaw cast iron chuck DK11-250/D6 is a professional lathe chuck with a diameter of 250 mm and a weight of 32 kg. Krollit, official Bernardo distributor since 2007.
- Chuck size: 250/D6
- D - Diameter: 250 mm
- Taper: 6
- D1 (max.): 106.390 mm
- D2: 133.4 mm
- D3: 70 mm
Who uses the DK11-250/D6 3-jaw cast iron chuck and for what
Mechanical workshops and artisan turners use the DK11-250/D6 3-jaw cast iron 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 3-jaw cast iron chuck DK11-250/D6 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.
Krollit logistics and support
Shipping 3-5 working days from Krollit warehouse for spare parts and accessories. Customer assistance in Italian available for technical documentation and compatibility verification with the reference machine. Krollit has been an official distributor since 2007.
Who is the DK11-250/D6 3-jaw cast iron chuck for?
The DK11-250/D6 3-jaw cast iron 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.
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Users with a Bernardo lathe with a compatible flange: original replacement or upgrade for Bernardo range lathes (Profi, Hobby, etc.) with A2 mounting conforming to DIN 55029.
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Irregular or non-round workpieces: for non-symmetrically centered workpieces, consider 4-jaw independent chucks or universal platforms.
Technical specifications
| Chuck size |
250/D6 |
| D - Diameter |
250 mm |
| Taper |
6 |
| D1 (max.) |
106.390 mm |
| D2 |
133.4 mm |
| D3 |
70 mm |
| H1 |
96.5 mm |
| Max. speed |
1600 rpm |
| Approx. weight |
32 kg |
Frequently Asked Questions
When to use a 3-jaw chuck?
Self-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).
It 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).
Why a cast iron chuck?
Cast iron chucks (DK Camlock or PS series) offer excellent thermal dissipation and a robust structure at a lower cost compared to steel.
Cast iron: typical concentricity precision 0.03-0.1 mm. The DK Camlock series has quick mounting, the PS is the basic model. High service life in standard machining operations.
What workpieces is the Ø 250 mm diameter suitable for?
Suitable for medium workpieces (max Ø ~220 mm): professional lathes.
The nominal diameter of the chuck indicates the maximum size of the body, not that of the workable part. The clamping capacity depends on the jaw opening (typically 60-70% of the nominal Ø).
What does the D6 mounting indicate?
The D6 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.
Check the mounting of your lathe before purchase: the interface flange must exactly match the code. Camlock = quick clamping with cams, disassembly in 30 seconds without tools.
How to maintain chuck precision?
Regular cleaning of the spiral 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.
