A point no-one has mentioned but Cornish Jack approaches, is one made in the old reference books.
It is that the edge of the tool should be under the clapper-box fulcrum. The swan-necked tool Jack describes can help achieve that as well as adding that resilience he mentions.
A tool that is not so located may be one factor in it becoming dulled prematurely, but I don't know if anyone has investigated this.
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My shaper is a manual Drummond, not a powered machine, but it's still possible to shock-load the tool and machine by too deep a cut. I always file a small chamfer on the entry edge to ease the tool in a little. I don't know if it actually makes much difference but it doesn't do any harm.
Regarding the impacts, think of a large face-mill with inserted tungsten-carbide shapes: that is often used at high speed but doesn't seem to mind. In fact I worry more about the hammering such operations can give the machine bearings, than the tips themselves.
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it was me, by the way, who had asked about hard surfaces on hot-rolled steel. Oddly, some steel I was turning today seemed slightly inhomogenous, indicated by unusual changes in the swarf along the cut. The material was 18mm diameter mild-steel of probably BS Somewhere-Handy spec., as it had been a cable-drum tie-rod so not needing to be anything too particular.