What method was used to kindle the Beltane 'need-fire'?

The Beltane “need-fire” was kindled by friction.

A need-fire was a ritual fire made by rubbing or drilling one piece of wood against another, rather than by using an existing flame, flint or a metal tool. In Scottish Gaelic tradition it was known as tein’ èiginn. The method gave the fire a deliberately “new” or ritually pure origin.

Accounts describe a large wooden fire drill, often made from oak. In some traditions, a designated group—famously nine men in certain Scottish accounts—worked the drill after metal objects had been removed and ordinary household fires had been extinguished. The resulting flame could then rekindle the community’s hearths.

The fire was associated with protection from illness, witchcraft and other supernatural dangers. Cattle might be driven between Beltane fires or near the flames, linking the ritual to the seasonal movement of livestock to summer pasture. Need-fire customs also appeared elsewhere in Europe, sometimes during outbreaks of cattle disease or plague, so the practice was broader than Beltane alone.