Dec. 05, 2025
Choosing the Right Chuck Enhances Machine Tool Performance
A chuck is a mechanical device used on a machine tool to clamp workpieces.
It's a machine tool accessory that uses the radial movement of movable jaws evenly distributed on the chuck body to clamp and position the workpiece.
A chuck generally consists of three parts: the chuck body, the movable jaws, and the jaw drive mechanism.
The chuck body diameter ranges from a minimum of 65 mm to a maximum of 1500 mm.
It has a central through-hole to allow the workpiece or bar stock to pass through;
the back has a cylindrical or short conical structure, which connects directly or via a flange to the end of the machine tool spindle.
Chucks are commonly used on lathes, external cylindrical grinders, and internal cylindrical grinders,
and can also be used with various indexing devices on milling machines and drilling machines.
To achieve better accuracy and stability in machine tool processing, the chuck becomes an important "bonus."
01. Solutions for Complex Parts with Multiple Facets
The following are some complex parts with multiple faces. Multiple clamping is obviously a "wasteful" solution, but because they have multiple machining surfaces,
a single clamping scheme requires special design. Indexing chucks are special chucks designed specifically for this type of workpiece.
They replace traditional lathe chucks to achieve automatic indexing of multi-faceted workpieces in a single clamping operation,
enabling multi-faceted repositioning and multi-process turning machining.
02. Principle and Characteristics of Indexing Chucks
● Can perform machining on multiple faces (8×45° or 6×60°) of the same workpiece in a single clamping operation;
● Achieves angular deviation within 1' and repeatability within 0.01mm;
● The chuck has a built-in clamping force compensation device to eliminate the influence of centrifugal force on clamping during chuck rotation.
As shown in Figure 1, the indexing chuck consists of two parts: indexing and clamping. The indexing part performs the chuck's indexing function,
and the clamping part performs the chuck's clamping function. Indexing is achieved while the product is clamped. As shown in Figure 2,
the indexing of the chuck is achieved by two push rods (a 45-degree push rod and a 90-degree push rod) driving the rotating shaft to rotate.
The 45-degree push rod pushes the chuck forward to the 45-degree position, and the 90-degree push rod pushes the chuck forward to the 90-degree position.
The positions of the two push rods are interlocked.
System Composition and Application of Indexing Chucks
The entire process of indexing chuck machining, as shown in the figure, includes components such as a hydraulic station,
distributor, flange, connecting rod assembly, and optional jamming alarm:
03. Application Scenarios
The main applications in the machining of parts are automotive parts, hydraulic valve parts, and engineering and mining machinery products:
▲Automotive parts
▲Engineering and mining machinery products
▲Hydraulic valve parts
04. Maintenance
To ensure that the lathe chuck maintains good accuracy even after long-term use, lubrication is extremely important.
Improper or inappropriate lubrication will lead to abnormal function at low pressure, weakened clamping force,
poor clamping accuracy, abnormal wear and jamming, etc. Therefore, the chuck must be properly lubricated.
