BT-BTA broaching systems were developed to machine internal/external keyway seats on CNC machine tools.

Thanks to these tools, in fact, it’s possible to start and finish the production of a piece on the same machine tool: it’s not necessary to change machine anymore, because the broaching operation can be planed after the turning, the drilling, the milling, ect. This leads to great savings in time, money and precision of the machining.

Brighetti Meccanica offers two solutions to broach internal/external keyway seats.

The first is the BT system – made up of the insert and the holder. This system is suitable when slotting machines or machine tools with “Y” axis are to be used. CNC software will guarantee the exact alignment between the tools and the piece. The holder is available with two cylindrical connections: Ø 25 e Ø 32. The machining depth goes from 30 mm to 200 mm.

The second system is called BTA, made up of the BT system (insert + holder) and the graduated eccentric bush. This three pieces system is suitable when machine tools without “Y” axis are to be used. When the machine tool doesn’t have the “Y” axis, in fact, the concentricity between the tools and the piece can be reached by setting up the eccentric bush.

Thanks to the graduated scale engraved on the collar of the bush, it’s possible to correct concentricity errors which are frequent in these kind of machining. The eccentric bush is available with three different sizes of the external diameter: 32-40-50, while the axis of the internal hole is 0,5 mm out of the centre.

BTA system, for which a patent has been released, is a great novelty in the field of keyways machining on CNC. At the time being, in fact, all the keyways broaching systems on CNC machine tools, available in the market involve “unmovable tools”, which means that the tools are not adjustable. As a consequence, the correction of the alignment of the tools needs several attempts and it’s not driven by a graduated scale, which, in the case of BTA, made this operation faster and easier.