Special tools come into play in a variety of applications: from large-scale manufacturing right down to small-batch production and individual components. When a standard tool simply won’t cut it for a specific machining operation, or when the production process for a series component needs to be optimised, special tools are the answer. The degree of customisation is also wide-ranging: from something as simple as a specific angle on the main cutting edge of a grooving tool, all the way up to a multi-level, complex milling tool. Special tool solutions always aim to reduce costs, increase process reliability and optimise production processes. With our large range of special solutions, HORN has the expertise to provide the answers to many machining challenges. We not only design and produce special tools, but also develop special machining processes.

Polygon turning? By adopting an axial feed approach, HORN tools enable you to produce non-circular contours on lathes consistently. During operation, the workpiece and tool axes are offset in relation to one another and a specific speed ratio is established between them. The tools are suitable for external and internal machining alike. Together, the axis offset, workpiece-to-tool speed ratio and circle of rotation of the cutting edge define the dimensions of the contour. Every tool system for polygon turning is individually tailored to the workpiece contour to be produced.

The technique is also suitable for series production because no jerky movements or reversals of motion occur during machining.

For face grooving of titanium sensor components, HORN engineers developed a machining solution based on the HORN Mini tool system. As well as being suitable for numerous standard versions of the system, the blanks can also be ground with customised cutting edge profiles. Three different customer-specific tools are used to create the profile for a face groove. The groove contour, the very tight form and geometric tolerances of the small workpiece and the high surface quality to be achieved meant that sequential cutting operations were necessary. The initial tool cuts the first inner contour, leaving a finishing allowance on the face. The second tool copies the conical shape and inner diameter in two axes. The third cut is made – as a finishing operation – on the bottom face by tool number three. To achieve this, the insert moves into the workpiece along two axes so that it can machine the face by performing an axial motion. The face subsequently acts as a functional surface of the component and tight tolerances apply in respect of the surface quality to be achieved.

Another special tool solution is deployed in the production of a stainless steel component. The customer contacted the HORN sales team with a request to optimise the machining process. After analysing the production strategy, the engineer recommended machining the contour with a double-edged special tool. The profile of the precision-ground cutting edges matches the workpiece contour, which means that the outer contour – including the face – can be machined in a single cut. The HORN engineers selected the type 316 triple-edged insert for the 5 mm (0.197") deep contour. The tool is designed to work like a counterbore to machine a contour in the workpiece in an axial motion. As it produces two identical cuts, the cutting pressure is balanced and the production line can run at double the feed rate.

Outstanding expertise

In addition to 25,000 standard solutions, the HORN range of over 150,000 special solutions means that we have the expertise required to precisely tailor tools to the customer’s production process. Special tools can help to optimise machining steps in both large-scale series production and small-batch production. Virtually all HORN insert types can be customised; the tool holder is also tailor-made for the application. The only limits on the design are the tool interface, the design of the machine and the type of machining performed.