Boring |
Our standard tools can reach a minimum of 6 times the bore diameter into your workpiece. If you need to go deeper, ask us for a special. If you have the choice between different standard tools, put together your tool according to the following specification:
- shortest possible length, largest possible diameter of tool shanks, and positive inserts to reduce deflection
- light cutting units to improve dynamic behaviour and effect of a possible damper
- large entering angles and small nose radiuses to reduce the radial forces, deflection and risk for vibrations
 Coromant Duobore rough boring tools give three different options ; First you can go Twin-Edge with two insert with the same length and diameter, which in theory can give you double the axial feed compared to a Single-Edge tool. But as the biggest cutting force will rapidly alter between these two competing inserts, and hence use any possible play in the tool and spindle, you might have to reduce radial depth of cut to avoid vibrations. Twin-Edge set-up can be used both in through-going holes and against shoulders.
 Second, add a standard shim under one of the slides to bring it a small distance up front from the other, and adjust it to only take the inner half of the desired radial cut, and you have a Step-Boring tool. Step boring is the solution if you want to take a larger radial cut than one insert can take, but remember to reduce the axial feed to what is normal for a tool with only one cutting edge. If the two inserts are set to take the same radial depth of cut, the outer one will always take the largest cutting force due to higher speed and more chip removal. In this case it is fairly easy to avoid vibrations. A smooth surface is guaranteed. This set-up will produce a stepped shoulder if it is not going through the work-piece.
Third, replace one of the slides with a standard protection cap, and you have a Single-Edge boring tool. Single-Edge boring is the first choice if the predrilled hole is somewhat out of the required finishing position, if you have problems with vibrations, close diameter tolerances, accurate roundness and/or good surface finish is required.
Our fine-boring tools are of course Single-Edge tools with radial micrometer adjustment on the cutting unit slide. They will outperform the rough-boring tools when you need to set up for close diameter tolerance, and will in general have cutting units for smaller inserts that are more suitable for finishing. | |
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Silent Tools® is a definition of
tool holder made to reduce
vibrations due to a damper inside
the tool body and is a trade mark of
Teeness ASA. Damped boring bars are
designed for high productivity,
close tolerances and overhang beyond
4 x the bar diameter.
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