Hainbuch Collets

Hainbuch is a specialist German manufacturer of high-precision workholding and clamping systems, headquartered in Benzingen.

Founded in 1946, the company has built a worldwide reputation for innovation and quality in workholding, with a particular focus on collet chuck technology for turning, milling & grinding applications.

Hainbuch's products are used in industries where concentricity, clamping force and repeat accuracy are critical including automotive, aerospace, medical manufacturing, precision engineering and bar-fed turning.

The company holds numerous patents and is recognised as a leader in modular clamping system design.

Hainbuch products we carry are centred around the Hainbuch modular clamping system and specifically the clamping heads that form the core of the system.

The range includes clamping heads in three chuck sizes (SK52, SK65 & SK80) available with either serrated or smooth clamping profiles and suitable for round, square and hexagon workpiece profiles.

Clamping diameters range from as small as 3 mm up to large-diameter workpieces, covering everything from micro-precision work to heavy-duty machining.

These clamping heads are designed for use with Hainbuch's modular clamping devices, which adapt to a wide range of machine tools.

The Hainbuch modular clamping system is a family of clamping devices and heads that share a common interface, allowing a single base clamping unit to accept a wide variety of clamping heads and adapt to many different workpieces.

he system is built around the principle that one base device can serve multiple operations. For example, the same modular clamping unit can clamp on the outside diameter, inside diameter, or via a three-jaw or face-clamping head, simply by swapping the clamping head.

This modularity reduces tooling inventory, shortens changeover times and gives the user a flexible solution for complete machining of a part in a single setup.

SK52, SK65 & SK80 refer to the size of the Hainbuch modular clamping interface which is the connection between the clamping head and the base clamping device.

SK52 is the smallest, suitable for lighter, smaller-diameter workpieces and lower-torque applications.

SK65 is the mid-range size, offering a good balance of clamping capacity and rigidity for most general machining.

SK80 is the largest, designed for larger-diameter workpieces, higher clamping forces and heavier machining operations.

The chuck size is determined by the base clamping device fitted to the machine and the clamping head must match that size to connect correctly.

Serrated clamping heads have a fine tooth-like serration on the clamping surface that bites slightly into the workpiece when clamped. This provides very high torque transmission and anti-rotation security, making serrated heads ideal for heavy machining, milling and operations where the workpiece must not slip.

The serration does leave light marks on the clamped surface, so they are typically used on as-machined or non-critical surfaces. Smooth clamping heads have a plain clamping surface that grips without marking, making them suitable for finished or delicate surfaces where witness marks must be avoided, such as ground shafts, thin-walled tubes and precision components.

The Hainbuch range can clamp round, square and hexagon profiles.

Round clamping is the most common and is used for shafts, tubes, rings and turned components (the collet-style clamping head grips the full circumference for excellent concentricity).

Square clamping is used for square bar, square tubes and components with square features and is particularly useful in milling and grinding where four-axis workholding is required.

Hexagon clamping is used for hex bar, nuts, bolts and other hexagonal components allowing accurate location and machining relative to the hex features.

This profile versatility is a key advantage of the Hainbuch modular system!

The Hainbuch range covers an extensive spread of clamping diameters from as small as 3 mm for micro-precision work and small-diameter components through the common turning and milling sizes (6 mm, 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm & 32 mm) up to large diameters for heavy workpieces.

Half-millimetre increments (e.g 6.5 mm, 7.5 mm, 8.5 mm) are available across the range, allowing precise matching of the clamping head to the workpiece diameter for optimal grip and concentricity.

The correct clamping diameter is critical because a head that is too large or too small will not clamp securely or accurately.

The MANDO Adapt is a Hainbuch adaptation device that allows a mandrel (internal clamping) to be used within a Hainbuch clamping device without detaching the base unit from the machine.

It provides a mandrel-in-clamping-device solution, enabling the user to switch quickly between external (OD) and internal (ID) clamping (typically in one to two minutes) without removing or re-setting the base clamping unit.

The MANDO Adapt offers a large clamping range, vibration dampening for better surface finish and is available for the 42 mm, 52 mm, 65 mm, 80 mm & 100 mm Hainbuch modular sizes, giving a mandrel clamping range of 13 mm to 100 mm diameter.

Concentricity = the accuracy with which the clamped workpiece is centred relative to the machine spindle axis is critical in precision machining.

Poor concentricity means the workpiece is off-centre, which causes run-out, inaccurate features, uneven stock removal, poor surface finish & accelerated tool wear.

Hainbuch collet-style clamping heads are engineered to deliver very high concentricity, typically within a few micrometres, because the clamping head grips the full circumference of the workpiece rather than at discrete points (as with a three-jaw chuck).

This makes Hainbuch the preferred choice for high-precision turning, grinding and boring where concentricity is a primary quality requirement.

Collet-style clamping (as used by Hainbuch) grips the workpiece around its full circumference, distributing the clamping force evenly and centring the workpiece accurately.

Three-jaw chucks grip at three discrete points, which can distort thin-walled parts, produce lower concentricity and leave jaw marks, whereas collet clamping delivers higher concentricity, lower risk of workpiece distortion, better torque transmission (with serrated collets) and faster changeover between workpiece sizes.

The trade-off is that collet clamping requires a clamping head matched to each workpiece diameter, whereas a three-jaw chuck can accommodate a range of diameters with manual jaw adjustment.

Hainbuch's modular system bridges this gap with quick-change heads.

One of the key benefits of the Hainbuch modular system is fast changeover. Clamping heads can typically be swapped in a matter of seconds to a couple of minutes, depending on the head type and size, without removing the base clamping device from the machine.

The MANDO Adapt for example, allows conversion between OD & ID clamping in one to two minutes without detaching the basic clamping device. This rapid changeover minimises machine downtime between jobs, supports flexible manufacturing and lights-out production, and allows a single machine to handle a wide variety of workpieces efficiently which is a major productivity advantage in subcontract and job-shop environments.

Hainbuch modular clamping systems are suitable for a wide range of machine tools, including CNC lathes, turning centres, turn-mill machines, grinding machines, machining centres and rotary transfer machines.

The system adapts to different machine spindles via appropriate mounting interfaces (such as A-type or direct-mount or via standard chuck interfaces).

Hainbuch systems are used extensively on bar-fed lathes (where the compact clamping head allows the bar to pass through), CNC turning centres (where concentricity and quick changeover are valued) and grinding machines (where run-out accuracy is critical).

Our engineers can advise on the correct Hainbuch configuration for a specific machine tool.

Hainbuch systems are used across a very broad range of applications.

• In precision turning they grip shafts, tubes & rings with high concentricity

• In grinding they hold components for cylindrical, internal and surface grinding with minimal run-out

• In milling and turn-milling they hold workpieces for multi-axis complete machining

• In medical manufacturing they grip small, precision components such as implants and instruments

• In automotive and aerospace, they handle production volumes of critical components requiring repeatable accuracy.

The ability to clamp round, square a& hex profiles and to switch between OD, ID & face clamping, makes Hainbuch a versatile choice for many workholding challenges.

Selecting the correct clamping head requires knowing the machine's base clamping device and its chuck size (SK52, SK65 or SK80), the workpiece profile (round, square or hexagon), the workpiece diameter or size, whether the clamped surface can tolerate marks (serrated) or must be unmarked (smooth) and the type of machining operation (turning, milling, grinding, heavy or light cuts).

The clamping head must match the base device size and the workpiece must fall within the head's clamping range.

For complete machining in a single setup, consider whether an adaptation device such as the MANDO Adapt would allow OD & ID clamping from one base unit.

Our in-house engineers can advise on the full configuration.