I get this question a whole lot:
"Does Dual Contact (aka BIGPlus) make a difference?"
Before I answer, let me say that we are neutral. We are not endorsing any product or brand or system. We only have our experience of testing tens of thousands of tool assemblies.
So, the answer is: MAYBE...PROBABLY...MOST OF THE TIME
The reason for that non-answer is that if we are comparing a dual contact (where the taper and flange have simultaneous contact with the spindle) tool assembly and a conventional gapped one they are never the exact same dimensions of projection, wall thickness, taper, weight, etc. So it is not apples to apples and we don't know what really causes the differences in measurement results and performance. But, we have a good idea. So, in most cases the dual contact tool is stiffer and stiffer usually leads to higher speeds. Usually. Sometimes the added stiffness puts the most stable lobe beyond the speed capacity of the machine. Some longer, smaller diameter endmills or long projection holders are so flexible that they really don't benefit from the added stiffness of the dual contact.
I have learned of another non-scientific answer and I will post that next.
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