438. Making the Length Equal the Circumference

Tefillin, Mezuzah v’Sefer Torah 9:2

Margins must be left in a sefer Torah as follows: below the text - four thumb-widths; above the text - three thumb-widths; between the columns, two thumb-widths. The sofer should leave an additional thumb-width at the start and end of each piece of parchment, plus room to sew the sheets of parchment together. When all the pieces of parchment are sewn together, there will be two thumb-widths between columns throughout. One should also leave parchment at the beginning and the end to wrap around the rollers. All of these things are merely the optimum way of doing things; if more or less parchment is left, the Torah is still valid.

Tefillin, Mezuzah v’Sefer Torah 9:3

Here’s how a Torah is made so that its length is equal to its circumference: one starts by making equal-sized pieces of parchment six handbreadths wide (around 18”). He wraps the parchments, making one tight roll. He adds to this roll, winding additional parchments tightly until the roll is six handbreadths in circumference, which is the same as the width of the parchment. He measures with a red string that is long enough to go around the roll.