There is disclosed a solid fuel rocket motor including a center-perforated solid fuel grain.

The solid fuel grain may be adapted to burn outwardly from a center surface facing the center perforation when ignited by a primary igniter during a normal mode of operation.

The central hole (70) and the perforations (120) are progressively stamped until they have burnished faces (130) perpendicular to the sides of the sheet (90).

The step of the method is to punch a central hole (70) and a circular array of closely adjacent perforations (120) in a generally planar sheet (90).

The central perforation appears to serve to fix the plaque to the wall with a peg, probably in the votive part of a sanctuary.

The collar (106) has a central portion with one or more perforations (202).

In between said bottom flap and said central portion, a first perforation line (12) is disposed.

There is disclosed a solid fuel rocket motor including a center-perforated solid fuel grain.

Each porthole area surrounds a porthole having a porthole edge (25).

Each perforation includes a perforation axis extending longitudinally through a center of the perforation.

Finally a central opening is formed in the body, preferably by punching the central portion of the body, thereby forming a raw matrix with a resist coating extending from the peripheral edge of the central opening.

The puncture apparatus comprises a rotatable puncture member (3).

This effects a sealing during punching.

The perforation tool assembly comprises an energy train, a first perforation gun, and a second perforation gun.

The punch pins are configured to punch through the stack of sheets during a punch stroke, the punch stroke defining a force profile.