Blind hole

As a blind hole is called in manufacturing technology, which does not completely penetrate the workpiece, so it has a certain depth. Blind holes are drilled, when

• The material thickness of the workpiece very large and a puncture is not necessary (in which case the depth usually of minor importance ) or

• A puncture for design reasons (sealing, stability, reliability ) is not possible. Then the intended depth must be adhered to exactly.

Blind holes are usually the fastening or locking other using screws or pins. You can also threaded, running conical or cylindrical and be consumed for the production of a fit with a reamer.

In wood blind holes are made ​​with the help of Forstner drill bits.

If the requirements for accuracy are not too high, blind holes in castings and modern materials such as plastics, sintered materials, etc. are also incorporated directly in the production by casting or pressing. If necessary, a post-processing by drilling, reaming or tapping is then necessary.

To remove, for example, iron filings, which are to remain through the hole in metal workpieces in a blind hole, a blind hole - magnet is used. Alternatively, the chips can be blown out with compressed air.

In the manufacture of multilayer printed circuit boards ( multilayers ) in electrical blind holes are used to connect an outer layer having an inner layer and for example to make a contact between the first and second wiring layer. Since the underneath layers are then not affected by a borehole can still run conductor tracks there as opposed to fully drilled through holes ( vias complete ).