The Bernardo PS3-250 3-jaw cast iron chuck is a professional-grade lathe chuck, weighing 29 kg. Krollit, official Bernardo distributor since 2007.
- Chuck size A: 250
- B: 85 mm
- C: 5 mm
- d: 200 mm
- E: 76 mm
- F: 224 mm
Who uses the PS3-250 3-jaw cast iron chuck and for what
Mechanical workshops and artisan turners use the PS3-250 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 PS3-250 3-jaw cast iron 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 within 3-5 working 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 PS3-250 3-jaw cast iron chuck for?
The PS3-250 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 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 according to DIN 55029.
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Irregular or non-round workpieces: for non-symmetrically centered workpieces, consider 4-jaw independent chucks or universal faceplates.
Technical specifications
| B |
85 mm |
| C |
5 mm |
| d |
200 mm |
| E |
76 mm |
| F |
224 mm |
| G |
M12 |
| h |
105 mm |
| J |
34 mm |
| Chuck size A |
250 |
| Max. speed |
2000 rpm |
| Approx. weight |
29 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 of 0.03-0.1 mm. The DK Camlock series has a quick-change mount, 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 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 M- mount) 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 the chuck's 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.
