The Bernardo PS4-400 4-jaw chuck is a professional-grade lathe chuck, weighing 85 kg. Krollit, official Bernardo distributor since 2007.
- Chuck size A: 400
- B: 105 mm
- C: 5 mm
- d: 330 mm
- E: 136 mm
- F: 362 mm
Who uses the PS4-400 4-jaw chuck and for what purpose
Machine shops and artisan turners use the PS4-400 4-jaw chuck as a clamping accessory on metal lathes, ensuring secure clamping and workpiece centering during turning, drilling, and grooving operations.
Its place in the Bernardo range
The Bernardo PS4-400 4-jaw chuck 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 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 PS4-400 4-jaw chuck for
The PS4-400 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 a metal lathe 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 spindle nose conforming to DIN 55029.
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Irregular or non-round workpieces: for asymmetrically off-center workpieces, consider independent 4-jaw chucks or universal faceplates.
Technical specifications
| B |
105 mm |
| C |
5 mm |
| d |
330 mm |
| E |
136 mm |
| F |
362 mm |
| G |
M16 |
| h |
145 mm |
| J |
55 mm |
| Chuck size A |
400 |
| Max. speed |
1000 rpm |
| Weight approx. |
85 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 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 body size, not the maximum workable workpiece size. Clamping capacity depends on 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 attachment 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 attachment. The lathe's technical documentation indicates the exact type.
How is chuck precision maintained?
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.
