The Bernardo 40–70 mm self-centering chuck is a lathe chuck for professional use available at Krollit, official Bernardo distributor since 2007.
- Clamping range: 40 – 70 mm
- Thread: M33 x 3.5 mm
- Area of use: Professional and advanced hobbyist
Who uses the 40–70 mm self-centering chuck and for what
Machine shops and artisan turners use the 40–70 mm self-centering 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 40–70 mm self-centering 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 performance levels: 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 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 40–70 mm self-centering chuck for?
The 40–70 mm self-centering 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 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 lathes (Profi, Hobby, etc.) with A2 mounting 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 platforms.
Frequently Asked Questions
What type of mounting does the 40–70 mm self-centering chuck have?
Check the indicated mounting in the title or specifications (typically A2-5, A2-6, A2-8 according to DIN 55029).
The A2 flange mounting is the standard for Bernardo Profi and Hobby range lathes. The number (5, 6, 8) indicates the flange size which must match the lathe's headstock.
How many jaws does it have and are they reversible?
Standard self-centering chucks have 3 jaws; typically supplied with 1 set of internal and 1 set of external reversible jaws plus a chuck key.
3-jaw chucks are suitable for round or hexagonal workpieces. For square or irregular workpieces, consider 4-jaw independent chucks. Soft jaws can be machined on the lathe for special applications.
What is the maximum rotational speed?
See "Max speed" in the technical table: typically 2,500-3,500 rpm for chucks up to Ø 200 mm.
The maximum speed decreases with diameter. Large chucks (Ø 400+ mm) have typical limits of 1,500-2,000 rpm. Exceeding the maximum speed risks jaw detachment.
What concentricity precision does it offer?
Professional Bernardo chucks comply with DIN 8386 class with a typical concentricity of 0.03-0.04 mm.
Concentricity is critical for precision finishes. For high-precision machining (microns), higher-class chucks or dedicated clamping collets are needed.
How is it mounted on the lathe?
The chuck mounts directly onto the headstock flange via a camlock for A2 systems.
The Camlock system allows for quick mounting without an additional adapter flange. For lathes with threaded spindles, a dedicated adapter flange is required. Krollit supplies compatible flanges separately.
