A nip former includes a base, an enhanced thermal conductor including an insertion hole, and a securing member including an inserting portion to be inserted into the insertion hole to attach the securing member to the enhanced thermal conductor such that the enhanced thermal conductor and the securing member sandwich the base. The inserting portion has a width that is smaller than a width of the insertion hole in a pressurization direction of an opposed rotator that presses against the nip former via a belt. The inserting portion does not contact an upstream wall and a downstream wall of the insertion hole in the pressurization direction of the opposed rotator and a direction opposite the pressurization direction of the opposed rotator in a state in which the securing member is secured to the base and the opposed rotator presses against the enhanced thermal conductor via the belt.