Bernardo 4-jaw chuck DK12-315/D8 is a lathe chuck for professional use, with a diameter of 315 mm, weighing 51 kg. Krollit, official Bernardo distributor since 2007.
- Chuck size: 315/D8
- D - Diameter: 315 mm
- Taper: 8
- D1 (max.): 139.734 mm
- D2: 171.4 mm
- D3: 100 mm
Who uses the DK12-315/D8 4-jaw chuck and for what
Mechanical workshops and artisan turners use the DK12-315/D8 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 DK12-315/D8 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 levels: 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 within 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 DK12-315/D8 4-jaw chuck for
The dk12-315/d8 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 during 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 mount conforming to 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
| Chuck size |
315/D8 |
| D - Diameter |
315 mm |
| Taper |
8 |
| D1 (max.) |
139.734 mm |
| D2 |
171.4 mm |
| D3 |
100 mm |
| H1 |
113 mm |
| Max. speed |
1200 rpm |
| Approx. weight |
51 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 type) clamps square or octagonal workpieces symmetrically. For off-center (eccentric, asymmetrical) 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.
Which workpieces is the Ø 315 mm diameter suitable for?
Suitable for medium-large workpieces (max. Ø ~360 mm): industrial lathes.
The nominal chuck diameter indicates the maximum body size, not the maximum workable workpiece size. The clamping capacity depends on the jaw opening (typically 60-70% of the nominal Ø).
What does the D8 mounting indicate?
The 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.
Check the mounting of your lathe before purchasing: the interface flange must precisely match the code. Camlock = quick clamping with cams, disassembly in 30 seconds without tools.
How is chuck precision 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.
