There is no tariff on Taiwanese machinery that I am aware of, but to some degree components that go into machines may have been effected as there is almost nothing that doesn't have a Chinese mainland component. One reason why the price gap between Chinese mainland machines and a similar Taiwanes machine has narrowed in 2020. Still across the board there have been incremental price hikes every year. Another forum member who purchased a Taiwanese lathe from Eisen the end of last year, the same model is now 20% higher in 2020.
As far as raw materials, I am not aware that if another country uses those materials that it effects the tariffs if the machine is imported from that country, and/or that it could be tracked back to the material source. One discussion I recall on this subject was that raw materials were routed to another non-tariff country and then imported into the US to bypass the tariff. Some items it may be similar to tariffs on automobiles were they need to show a breakdown of % source components to avoid a tariff.