A heat transfer tube (1) with a finned inner surface, which is divided into
at least two zones (Z.sub.1 to Z.sub.m) in peripheral direction. The fins
(2, 3), which extend at an angle of inclination .alpha. with respect to
the longitudinal axis of the tube, are arranged in the individual zones
(Z.sub.1 to Z.sub.m) in any desired periodic combination and sequence of
at least two fin heights (H.sub.1 to H.sub.n, H.sub.1 >H.sub.2 > . .
. >H.sub.n). Adjacent zones border thereby on one another so that the
fin sequence is staggered for at least one fin in longitudinal direction
of the tube. Modifications include the finned inner surface being divided
into groups of zones, in which the angle of inclination of the fins is
uniform, however, varies between adjacent groups.