Previously minimum quantity lubrication (MQL) was applied for this manufacturing step. After machining, the components had to therefore be disassembled, cleaned and remounted. In addition machining was often carried out in several successive machining steps. Different tools were used for drilling, reaming to the final diameter and countersinking. The complete process was therefore time-consuming, costly and the required dimensions were often not reliable. For example, the bore and countersinking often did not align on one axis.
To optimise this process, MAPAL has developed a drill with countersink step for dry machining. The special geometry of the tool ensures that the heat caused by machining is not transferred to the component. As a result, MQL can be eliminated and neither the component nor the working environment are contaminated with coolant.
The drill two cutting edges made of solid carbide combines the properties of a drill for machining aluminium with those of a drill for CFRP machining. It also has a double point angle. This ensures good centring of the drill and minimum burr formation at the bore outlet. Reliable removal of the chips is ensured by the specially designed chip spaces. Any delamination and fibre protrusion is to be avoided for the countersinking in the CFRP. MAPAL achieves this with a rake face correction at the countersink step. As CFRP is an extremely abrasive material, the drill is diamond-coated. This means that eight times the tool life is achieved compared with an uncoated drill.
The drilling/countersinking tool for the dry machining of CFRP aluminium stacks has been successfully used by customers. A speed of 5,000 rpm and a feed of 0.1 mm are applied. The tool is not only impressive in practice because of the results with regard to process reliability, tool life and the machining result, but also because of the steady boring process. The drill is available with a diameter between 4.1 and 11.11 mm with the associated countersink step.
MAPAL – tooling the customer’s success
MAPAL Präzisionswerkzeuge Dr. Kress KG is one of the leading international suppliers of precision tools for the machining of practically all materials. The company founded in 1950 supplies leading customers from the automotive and aerospace industries and from machine and plant engineering. With its innovations the family-owned company sets trends and standards in production and machining technology. MAPAL sees itself as a technology partner, supporting its customers with the development of efficient and resource-conserving machining processes using individual tool concepts. The company is represented with production facilities, sales subsidiaries and representatives in 44 countries worldwide. In 2016 the MAPAL Group had 5,000 employees, generating sales of EUR 575 million.
MAPAL Dr. Kress KG
Obere Bahnstr. 13
Telefon: +49 (7361) 585-0
Telefax: +49 (7361) 585-1029
Head of Marketing and Corporate Communications
Telefon: +49 (7361) 585-3683
Fax: +49 (7361) 585-1019
Telefon: +49 (7361) 585-3552
Fax: +49 (7361) 585-1029