Disclosed is a stapler including: a body including a fixed plate provided on a top portion of one end thereof and formed with a needle insertion hole, and a lower thread supplier provided below the fixed plate to feed a lower thread through the needle insertion hole; and a presser which is connected to the other end of the body at one end thereof by a rotating shaft, and includes a fastening needle installed to the other end to stitch an object and penetrating the needle insertion hole together with an upper thread, in which the object is stitched with the upper thread and the lower thread when pressure is applied to the presser. Since the sheets of paper are bound with the thread, it is possible to prevent the paper from being discolored or crumbed.

An embodiment is proposed for sewing book blocks. A related embodiment comprises, for each book block, forming one or more stitchings with corresponding threads ending with corresponding free loops on a last signature of the book block. The threads are brought in line with corresponding free loops and thus through them along an advancement line of the signatures. The threads are moved away from the free loops by means of corresponding hooks, with the threads sliding relative to the hooks in this phase, thereby tightening each free loop around its thread. After that, the threads are cut. A related bookbinding sewing machine and a related bookbinding plant are also proposed.

An embodiment is proposed for sewing book blocks. A related embodiment comprises, for each book block, forming one or more stitchings with corresponding threads ending with corresponding free loops on a last signature of the book block. The threads are brought in line with corresponding free loops and thus through them along an advancement line of the signatures. The threads are moved away from the free loops by means of corresponding hooks, with the threads sliding relative to the hooks in this phase, thereby tightening each free loop around its thread. After that, the threads are cut. A related bookbinding sewing machine and a related bookbinding plant are also proposed.