Mechanical processing

Machining GRP profiles is simple and similar to woodworking. The most common machining techniques are drilling, milling, sawing, turning, punching and threading.

For holes up to 12 mm diameter, a simple

carbide drill

according to DIN 8037 or DIN 8038 can be used. For holes larger than 12 mm in diameter, if possible use a diamond drill bit to use. To reduce fraying at the drill exit, a wooden pad should be used.

Drilling speed 60-80 m/min. Diamond-tipped drill 300 to 1200 m/min


For milling
carbide or diamond cutters are well suited for milling GRP. A higher feed rate can be achieved with carbide cutters. The use of a coolant is advisable, as GRP profiles are poor heat conductors.

Cutting speed 100 to 400 m/min


When sawing smaller quantities, a conventional
sufficient. For higher volumes, however, it is recommended to use a diamond-tipped saw blade. The diameter of the saw blades should be between 200 – 500 mm, depending on the wall thickness. In the case of dry processing, a

Cutting speed 1800 to 3600 m/min.


When turning of smaller quantities, a
standard equipment
sufficient as in conventional metalworking. For larger quantities, on the other hand, should
Carbide tools
as, for example, for brass or aluminum machining.
Water cooling is always advisable.

Cutting speed as for brass or aluminum.


For punching should be
Tools from hardened steel
be used. However, the material thickness of the workpiece to be machined should not exceed 10 mm.

Max. Punching material thickness = 10 mm


should only be cut if the connection is not subjected to too high a tensile load. The pull-out strength is about one-third that of metallic threads, but sufficient strength for many applications with an exact fit and the use of adhesives is quite feasible.

Pipe and trapezoidal threads allow better force transmission than metric threads


GRP can be
easily and firmly
with adhesive based on polyurethane and epoxy resins
. However, the instructions given should be observed.

1. roughen surface 2. remove dust 3. Degrease with solvent 4. Follow the manufacturer’s guidelines when applying the adhesive.


When riveting the hole should be slightly larger than the rivet diameter.
The use of adhesives to increase the bond strength is recommended

The use of adhesive increases the bond strength.


For lightly loaded connections
self-tapping screws
sufficient. For connections that are subjected to heavy loads, the Machine screws be used. The use of adhesives to increase bond strength is also recommended for bolting.


to be painted
The surface to be painted should be thoroughly cleaned and degreased with a solvent before the paint is applied. As a varnish, we recommend a polyurethane-based system.

Best coating results are achieved with 2-component PUR coatings.