There are Many things that can render Tefillin or Mezuzah not Kosher or at best minimally Kosher.
Some of which happen over time with aging and some unfortunately are Posul from the get go.
Letters, words and or Tagim that are missing, extra substituted, touching, Broken, Improperly Spaced, misshapen faded, cracked and weather damaged.
We document the problems we find and periodically upload them to the website.
We hope that this will educate and encourage the public to purchase only Tefillin and Mezuzas that are high quality from a reputable source, to take care of them properly and have them checked regularly.
A client brought these into the office explaining that his straps were ripped for a long time and he had been meaning to come in and get them replaced, but he kept pushing it off because his Chaver (Friend) told him as long as the straps are connected at some point they are still Kosher.
Unfortunately this could not be further from the truth!
Retzuos start out at 15mm in order that if they begin to tear you will still have some time to get them replaced before they become Possul.
The preferable (Kosher Lechatchilah) width is 11mm according to the Chazon Ish and 10mm according to Rav Chaim Naeh.
The minimal (Bedieved) width for making a Brachah is 9mm. If a Retzuah started tearing at one spot making the connected Retzuah it less than the minimal width it is Possul and must be replaced. The Retzuah in this picture is at most 4mm.
Lesson: Do not tie the straps on very tight or wrap them on the box very tightly as this will lead to eventual ripping and invalidating the Tefillin straps.
Rabbi Kass was ordained by Rabbi Yisrael Meir Lau, former Ashkenazik Chief Rabbi of Israel. He is certified as a Sofer for both Kesivah and Hagoah by one of the leading experts in Safrus, Rabbi Avrohom Tzvi Vosner, Rav of the Vad Mishmeres Sta”m.