Twist-spun knot
= Twist-spun knot
{title2=$\operatorname{Tw}_m(K)$}
An $m$-twist spin removes a trivial arc from a knot and spins the resulting knotted arc around the boundary of a three-ball in $S^4$, inserting $m$ full twists during one revolution.
The result is a <surface knot> with domain a two-sphere.