The standard in tool technology for grooving

When Paul Horn introduced the Type 312 changeover plate in 1972, it brought about a minor revolution in the field of grooving. The German company was the first manufacturer ever to present a three-track tool system with a stationary carbide chisel for grooving. In today's machining industry, processes such as crosscutting or radial, axial and internal grooving are daily business. The drive for innovation and technical perfection in HORN's DNA ensures that the manufacturer continues to set the standard in tool technology for this application today.

The Type 312 changeover plate is still very popular today. However, HORN has never stopped developing new solutions and optimizing even the most successful product series. Moreover, the tools are also used in their own production. Originally this insert was used almost exclusively in the automotive sector, but in the meantime the applications are much broader. Among others, the 312 is used for workpieces in medical technology, in the manufacture of hydraulic components and for everyday items such as jewelry or ballpoint pens. 

Since 1972, however, the tool specialist has developed many other tools that, like the Type 312 changeover plate, have been used successfully for grooving.

Grooving uses a narrow cutting edge that penetrates the workpiece in a radial or axial direction. Part of the art is to control the flow of chips. Clamping chips, chip accumulations or long ribbon chips must be avoided, as they have a negative impact on process reliability and can lead to flanks with scratches and tool breakage. Depending on the material being machined and the type of machining, HORN has developed different chip shape geometries that ensure process reliable chip deflection, chip guidance and chip breakage. 

The supply of cooling lubricant is also important. Modern tool carriers usually have an internal coolant supply, which provides effective cooling of the contact zone between the cutting edge of the tool and the workpiece. HORN also offers an S100 type cutting insert, which supplies the contact zone with high-pressure coolant directly through the cutting insert. 

Finally, the quality of the carbide used, the quality of the cutting edge and the coating of the cutting tool also play a decisive role for a reliable and economical separation process.

Trochoidal change plates are used on the shop floor to produce a wide and deep groove in an aerospace part. Indeed, these tools are well suited for producing deep and wide grooves where a large chip volume must be generated. Operators manufacture the part from 1.4548 (X5CrNiCuNb17-4-4), a high-strength and toughness steel. An S229 insert with a 2-mm radius is used for roughing. 

Groove making proceeds as follows: the groove 30 mm wide and 15 mm deep is trochoid rough cut with the full radius insert at a cutting speed of vc = 140 m/min with a depth of cut of ap = 1 mm. The feed rate is programmed with fn = 0.25 mm/rev. The finishing allowance is 0.2 mm. A cutting insert of the S229 system is also used for finishing. That finishing is done from two sides with a 3 mm wide groove plate. The corner radius is 0.2 mm. In less than two minutes, the groove is made.

A customer in the medical sector deployed the Type 105 Supermini system in the production of a thin-walled valve cover made of titanium for use with a cerebrospinal fluid shunt system. In addition to a tool for the axial parings, the operator also needed to have a special tool for finishing the fit of the lid. For this purpose, HORN developed the Supermini system with an angular radius of 0.05 mm. The challenges in machining titanium lie in heat dissipation and chip flow control. The customer's implants are also subject to strict criteria, including with regard to the surface. For example, there must certainly be no burrs. 

HORN's tools are ideal for such demanding applications. In the meantime, the tool specialist continues to invest heavily in the development of new tools and the optimization of existing products. Grooving, in other words machining between two flanks, remains one of the most important disciplines in this regard.