Machining Guidelines

TECASINT products can be machined wet or dry on all machine tools suitable for metal machining. The use of cutting tools made of carbide with a cutting edge angle for aluminium machining has proven the most successful for machining these materials. To avoid machining errors, it is important to detect and exchange worn indexable inserts in good time, and to use the recommended cutting and feed rates for the individual machining processes.

Deformation as a result of excessively high clamping pressure, in particular when machining thin-walled parts, must be avoided. Preferably, clamping sleeves, clamping mandrels or vacuum clamping fixtures should be used. The use of four-jaw chucks is recommended. A higher number of jaws results in improved distribution of the clamping force.

For machined parts with extremely close tolerances, the material should preferably be machined dry due to its hygroscopic behaviour. However, in this case attention should be paid to ensuring good heat dissipation during the machining operation.

TECASINT parts with large diameters tend to grow slightly immediately after piercing due to the high cutting pressure. Consequently it is advisable to always produce these in the lower tolerance band. Semi-finished products for the manufacture of extremely precise parts must be tempered prior to machining. An additional intermediate tempering process is generally not required during machining.

In order to prevent dimensional changes to the finished parts due to their hygroscopic behaviour, it is advisable to pack high-quality components in vacuum barrier film if they are expected to remain in storage for an extended period.

For all machining operations, the use of carbide tipped tools with the same geometry used in aluminium machining offers the best solution. The indexable insert tip should have a radius of between 0.2 and 0.4 mm. As a result of wet machining, the cutting pressure at the workpiece increases, which can give rise to increased burr formation. The service life of cutting tools can be substantially extended by wet machining,
Optically very appealing products with a good surface quality (Ra ≥ 1.6) can be achieved during the machining of PAI / PI products, if all the essential machining instructions are taken into account during turning.

Cutting speed for flat, longitudinal, cylindrical turning / grooving and piercing

V = 100 – 130 m/min. f = 0.05 – 0.25 mm / rev.

Milling is recommended exclusively with downcut milling.
The best solution for all machining methods is the use of carbide tipped tools with the same geometry used in aluminium machining. Individual grinding of cutting tools can produce even better results. Dry and wet machining are both possible.
As a result of wet machining, the cutting pressure at the workpiece is increased, which can cause increased burr formation to occur. The service life of the cutting tools is substantially extended by wet machining. Excessive single-sided application of heat into the material should be avoided. Alternating two-sided machining is recommended as the preferable method.

Face milling: V = 90 -100 m / min. f = 0.04 – 0.08 mm I tooth

Carbide drill bits are recommended for machining PAI and PI materials. The exception to this are boreholes less than 1.5 mm dia. These should be produced exclusively using HSS drill bits which should be ground to a pointed angle of 120°. To counteract the effects of heat generation, adequate chip removal and wet machining are recommended for all drilling processes. Carbide drill bit V = 100 m / min. f = 0.02 - 0.1 mm / rev.HSS drill bit V = 15 - 40 m / min f = 0.02 - 0.1 mm / rev. For detailed instructions on machining, please refer to our technical information sheet “Machining guidelines for TECASINT”