ERNST-GROB

eXTERNAL cold FORMING

 Cold Forming Technology for Precision Splines

Our cold forming solutions enable the efficient production of complex geometries with exceptional accuracy. By breaking down the forming process into numerous small steps, even high-strength steels can be formed to high degrees—resulting in ready-to-install splines with superior quality and consistency.

Advantages at a Glance:

• Excellent spline precision and repeatability
• Surface hardening during the forming process
• No disruption of material grain flow, ensuring maximum strength

This method offers a cost-effective, high-performance alternative to traditional machining—perfect for demanding applications.  

A9 & A9T Cold Rolling Machines
Flexible & Cost-Effective Forming
Modular machines adaptable to various forming needs—ideal for solid material and entry-level sheet metal forming. Supports Grob technologies like intermittent, cold, and stroke forming.

C6 Cold Rolling Machine
Precision for Fine Spline Modules
Engineered for cold forming small-module splines on solid stock, tubes, and hollow shafts—perfect for components like cardan shafts, hubs, and flanges.

C9 & C9T Cold Rolling Machines
Heavy-Duty Forming for Large Workpieces
Designed for large or long parts up to module 3.5. With an extended bed and torque drive, it handles splines up to 10,000 mm without reclamping.

C9T-Helix Cold Rolling Machine
Precision Forming for Helical Gears
Equipped with tilt-adjustable roller heads (±30°), the C9T-Helix enables efficient production of helical splines with consistent accuracy.

T12 Cold Forming Machine
High-Capacity Forming for Large Parts
Our largest model—ideal for forming clutch carriers, hollow parts, and large solid profiles. Built for demanding sheet metal and heavy-duty applications.

INTERMITTenT FORMING

Innovative Process for High-Precision Splining Without Axial Feed
Intermittent forming is Grob's proprietary solution that closes a crucial gap in modern forming technology. Designed for the fast and efficient production of complex external splines, this process uses specially developed kinematics that eliminate the need for axial feed. As a result, it enables splining operations with extremely short run-out zones, even when working close to a shoulder. This makes it ideal for applications that demand precision, repeatability, and minimal material distortion. Whether for small batch production or high-volume runs, intermittent forming delivers exceptional results with improved process reliability and shorter cycle times.

Advantages at a Glance:

• Enables splining up to one shoulder

• Universally applicable across a wide range of components

• Excellent surface finish (Ra 0.4 ~ N5) with minimal secondary processing 

InterNAL COLD FORMING

Internal Cold Forming for Highly Precise Splines
Our internal cold forming technology produces splines from the inside out, offering a new level of precision and flexibility. By eliminating the need for planetary motion around roller spindles, this method allows splines to be formed extremely close to shoulders—with virtually no gear run-out. The result is highly accurate, ready-to-use internal splines at lower tooling costs.

Advantages at a Glance:

• Minimal spline run-outs for improved accuracy

• Complete internal spline formation

• Cost-efficient tooling and setup

Internal cold forming provides an ideal solution for applications requiring tight tolerances and space-saving designs.

i9 Internal Forming Machine
Versatile Solutions for Internal Splines and Joining
Designed for forming internal splines in sheet metal and thick-walled parts. Also ideal for advanced joining applications like direct forming and clinching.

Slotting & coining

Slotting & Coining for Economical Sheet Metal Processing
Our slotting and coining technologies deliver efficient and flexible solutions for cup-shaped and ring-shaped sheet metal parts. By combining punching, embossing, and forming into a streamlined process, we ensure high precision and cost-effective production, even for complex geometries.

Advantages at a Glance:

• CNC-controlled process with correction capabilities

• Slotting operations performed step-by-step for greater accuracy

• Flexible choice of slotting direction

• Mechanically defined end of stroke for consistent results

Slotting and coining offer an ideal solution for achieving high-quality sheet metal components with reduced production costs

S8 Slotting Machine
Compact, Precise Slotting and Coining
A modular machine for slotting, coining, cutting, and forming sheet metal parts. Ideal for producing circlip grooves and combined slotting/coining operations.

Spinning

Spinning for Lightweight, High-Precision Forming
Our spinning process transforms flat, disc-shaped blanks into precision-formed, cup-shaped components. Using controlled pressure from spinning discs and a support mandrel, the material is shaped exactly to specification. Wall thicknesses can be selectively reduced for lightweight construction, and rolled grooves can be integrated to save material and reduce costs—making this process ideal for efficient, weight-optimized part production.

Advantages at a Glance:

• Low tooling costs for economical production

• Extremely short processing times

• Can be seamlessly combined with other forming processes

Spinning is an ideal solution for manufacturers seeking flexible, fast, and cost-efficient sheet metal forming.

R3 Spinning Machine
High-Speed Forming of Rotational Parts
Built for fast, precise production of light-gauge, symmetrical hollow parts. Also capable of forming features like grooves and recesses through metal spinning.