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String tore from the Tzitzis:
Although it was already explained that at the time that the Tzitzis is tied to the corner each of the eight strings must have a minimum length of 12 Gudlin, nevertheless this only applies when initially tying of the strings to corner. If, however, after the completion of the tying the strings tore and are no longer this length, then at times the Tzitzis still remains Kosher and is not required to be remade. A torn string that nevertheless remains valid is called Gardumei Tzitzis, or Tzitzis leftovers, and its validation is a tradition of Moshe from Sinai. The validity of a torn string is dependent on the following three factors:
- The area of the tear.
- The amount of strings that tore
- The amount that remains of the torn string.
Although in many of the situations to be explained, a torn string does not invalidate the Tzitzis, nevertheless, it is an act of piety followed by G-d fearing individuals to verify that the Tzitzis contains 8 full length strings of 24 cm. If any of the strings have torn to less than this length, a G-d fearing Jew is to undo the Tzitzis and tie new strings onto that corner.
The areas of the Tzitzis:
The Tzitzis is divided into three parts regarding the tearing laws.
- Below Gdil: The unbraided strings which extend out of the corner hole, and precede the braid [i.e. precede the first set of knots].
- Gdil: The braided part, which is from the first set of knots to the last set of knots
- Above Gdil/Anaf: The loose strings which extend past the last set of knots and dangle over the floor. These strings are referred to as the strings that extend above the Gdil.
Tore within the Gdil/braid, or beneath the Gdil by the hole?
If even one string tore from the root of the fringes, the Tzitzis is invalid. This means that if even one string tore near the corner hole, within the area that precedes the braid, or within any area of the braid, the Tzitzis is invalid. [Thus, any tear that occurs beneath the loose area called Anaf, invalidates the Tzitzis.]
What is the law if the string tore within the last set of knots from which the loose strings extend from?
Seemingly the Tzitzis is invalid.
What is the law if the string tore above the knots, but later unraveled and now protrudes from below the knot?
This matter requires further analysis.
One string tore above the Gdil/braid?
If a single string [of the 8 strings] tore in the area of loose strings that extends past the braid, called the Anaf, it is valid. This applies even if it completely tore until the actual start of the braid. [Nevertheless, it is an act of piety to always have 8 full strings of 24 cm, as explained above.]
- Two strings tore above the Gdil/braid?
If two strings tore in the area of the loose strings that extend past the braid, called the Anaf, then it is only invalid if this possibly caused an entire string of one of the four strings to be missing. Thus, if one of the two torn strings still retains the length of Kdei Aniva [4 cm] above the braid/knots, it is valid, even if the other string completely tore until the knot. Furthermore, even if both strings completely tore, but one knows for certain that the two torn strings are from two different strings of the original four long strings, the Tzitzis remain valid. If however one is uncertain as to whether the two torn strings are from two different strings of the four long strings, and it is hence possible that they are the two sides of the same long string, then the Tzitzis is invalid. This applies even if both strings did not completely tear but are both a length of less than Kdei Aniva [4 cm], nevertheless it is invalid. If however even one string retains a length of Kdei Aniva [4 cm], then the Tzitzis is valid as explained above.
How to determine that the two torn strings do not belong to the same long string: As stated above, when two strings tear below 4 cm, it is only valid if one knows for certain that the strings are not from the same string of one of the four long strings. This can be determined as follows: If at the time of tying the Tzitzis one made sure to separate the two sides of the four strings, with each side of four strings remaining on opposite ends throughout the entire braiding of the Tzitzis, then one knows for certain that the strings of each side contain their opposite end on the opposite side, and not on the same side. Hence, if two strings tore below 4 cm on the same side, the Tzitzis remains valid. If however the two strings tore below 4 cm on opposite sides, then the Tzitzis is invalid, as it is possible that the two sides of a single long string has torn. [It is possible to secure that each side of four strings remains together on the same side throughout the braid, through knotting the top of one of the sets of four, and only undoing the knot after the braid is complete. Alternatively, one can make a different sign on them, such as a pencil mark and the like.] If however one was not careful that the original sides of four strings remain together until the last knot of the braid, then even if the two strings tear on the same side to below 4 cm, the Tzitzis is invalid, as perhaps both of these strings are the two sides of one of the four long strings.
If two strings tore, then if one of the strings is still the length of Kdei Aniva [4cm], the Tzitzis is valid. If both strings are less than Kdei Aniva [4 cm], then if the two strings belong to two opposite sides, the Tzitzis is invalid. If the two strings tore from the same side, then if one made sure to keep the two sides of the four strings separated while making the braid, then the Tzitzis remains Kosher. If however one was not careful in the above, it is invalid.
If two strings completely tore up until the braid in a way that invalidates the Tzitzis, may one continue to wear them if there are no other Tzitzis available?
The Poskim rule that in such a case it is permitted to do so without a blessing and so rules Admur in the Shulchan Aruch. However, according to the ruling of Admur in the Siddur, it is implied that it is forbidden to continue to wear the Tzitzis even in such a case.
If one is unsure whether the Tzitzis were tied in a way that the sides remained separate throughout the tying, may one be lenient if two strings tore below Kdei Aniva on the same side
Three or more strings tore above the Gdil?
If three [or more] of the eight strings tore to the point that that they no longer contain the minimum length of 24 cm [measuring from the first knot near the corner] the Tzitzis is invalid in all circumstances. This applies even if the strings maintain a much greater length than Kdei Aniva [but all three are now less than 24 cm. from the knot]. [This applies irrelevant to which side the strings tore from, whether all three tore from the same side, or two tore from one side and another tore from the other side.]
What is one to do with a torn string?
Tzitzis strings that are no longer attached to a Tallis do not require Geniza, and may be discarded wherever one chooses, although one who is stringent should not discard it in a repulsive area. A Baal Nefesh places the Tzitzis strings in Geniza or into a Sefer to use as a bookmark. See Chapter 1 Halacha 17B!
If even one string tore within the Gdil [braid], it is invalid. If one string tore above the Gdil, it is valid even if it completely tore to until the knot. [However it is a Mitzvah Min Hamuvchar to always have eight full strings of 24 cm.] If two strings tore above the Gdil, then if one of the strings is still the length of Kdei Aniva [4cm], it is valid. If both strings are less than Kdei Aniva, it is only valid if one knows for certain that the strings are not from the same single string of the four strings. If one made sure to separate the strings of the two sides when he made the Tzitzis, then if two strings tore on the same side, it is valid, as one knows for certain that it is from two different strings. If however one was not careful in the above, it is invalid due to doubt. In all cases, if the two strings tore on two different sides it is invalid due to doubt that perhaps they are from the same string.] If three strings tore above the Gdil, then if there are three strings that do not reach a length of 24 cm the Tzitzis is invalid irrelevant to whether they maintain Kdei Aniva or to which side they come from.
What is the law if the bottom of a string partially tore and remains attached to the rest of the string through a mere thread?
The string is not considered torn.
If the strings of a Tzitzis tore and became invalid, may one unravel some of the loops in order to validate its length?
When replacing the Pasul Tzitzis of a corner, must one undo the Tzitzis of the other corners and retie them?
No. The concept of Taaseh Velo Min Hasuiy does not apply in such a case. If the Tzitzis of another corner has torn and is only Kosher Bedieved, see next Q&A!
If the Tzitzis of a corner became invalid and needs to be replaced, does it affect the Kashrus of the Tzitzis of the other corners and require it to be replaced?
Ø Example: If one set of Tzitzis has a string that tore and is less than 24 cm, and is thus only valid being that it was initially tied with the correct length, must it be replaced when replacing the invalid Tzitzis of another corner?
It is implied from the previous Q&A, that the invalidation of one corner has no effect on the fringes of the other corners, even if the Tzitzis of the other corners are initially invalid to be used.
Summary chart according to Siddur and Chabad custom
|One string tore in braid or below braid||Invalid|
|One string tore above braid||Valid|
|Two strings tore above braid on two opposite sides||Valid only if one string has 4cm length remaining|
|Two strings tore above braid on same side and kept sides separate||Valid|
|Two strings tore above braid on same side and did not keep sides separate||Valid only if one string has 4cm length remaining|
|Three strings tore above braid||Invalid if all three are no longer 24 cm long|
 Admur12:2-3; Siddur Admur
 This applies even if the other corners have yet to have Tzitzis placed on them, and one has not yet worn the Tzitzis. Hence, if prior to tying Tzitzis to the second corner, a string on the first corner tore, it still retains all the laws of Gardumei Tzitzis to be explained. [See Piskeiy Teshuvos 12 footnote 10]
Other opinions: Some Poskim rule one must complete the Tzitzis and wear it one time in order for the law of Gardumei Tzitzis to take effect. [Hisorerus Teshuvah 2:57]
 Chesed Lealafim 12:1; Ashel Avraham Butchach 12 in name of Rav Menachem Mendel of Rimnov; Rebbe Rayatz in Sefer Hasichos 1944:56; Rebbe in Igros Kodesh 13:29 [printed in Shulchan Menachem 1:41]; See Admur 15:5 that implies such a Chumra does exist; Makor Chaim 12:15; Sfas Emes Shabbos 118b; Kaf Hachaim 12:12; Shulchan Hatahor 15:1; Piskeiy Teshuvos 12 footnote 2
It is a clear ruling in Gemara and Poskim, as Halacha of Moshe from Sinai, that Gardumei Tzitzis are Kosher. It is not recorded in any previous Poskim that there is an act of piety involved in nevertheless not using such Tzitzis. Nonetheless, being that the above Tzaddikim do make mention of this Hiddur, therefore one is to abide by it and fulfill the Mitzvah of Emunas Chachamim. [Ashel Avraham Butchach ibid; See there that he went ahead and fixed his Tzitzis that had one torn string after he heard of this Hiddur from Rav M.M. of Rimnov.]
 The reason: As the 32 strings have Kabalistic meaning and hence one should always be careful that it retain this number. [Chesed Lealafim ibid] Having the 32 strings protects one from stumbling in matters of promiscuity [Piskeiy Teshuvos ibid in name of Sefarim]
If the string is still 4 cm long: If the torn string is 4 cm long, then some write it is not necessary from even a standpoint of piety to replace the Tzitzis, although one who in any event desires to do so out of Hiddur Mitzvah may do so. [Ashel Avraham ibid]
The prohibition of removing Kosher Tzitzis from a Tallis: Although it is forbidden to remove Kosher Tzitzis from a Tallis, nevertheless, it is permitted to do so if one of the strings have torn and one plans on placing another pair of Tzitzis on the corner, in order so one have 8 complete strings. This applies even if the tear did not invalidate the Tzitzis. [Admur 15:5] See Ashel Avraham ibid that questions this allowance, stating that perhaps it is forbidden to transgress the prohibition of removing Kosher Tzitzis for a matter that is not brought in Poskim, nevertheless he concludes that one may do so, as it is nevertheless a Hiddur. See however Shulchan Hatahor ibid that writes one is to reuse these same Tzitzis by tying another string to the torn area. Other Poskim are also stringent in this matter. [Mor Uketzia 15; Artzos Hachaim 15:2]
 Siddur Admur; Shlah Chulin 112a in interpretation of Rav in Menachos 39a; Elya Raba 8:10 in name of Taz and Shlah; Emek Haberacha 2:13; Soles Belula 12:2
The Gemara states that if a string tore in the “Ikkur” or root of the Tzitzis, the Tzitzis is invalid. There are various interpretations of this word “Ikkur”. Does it mean the “Anaf”, the loose strings; does it mean the Gdil, the braided area; does it mean the area below the braid, which is the strings that pass through the hole? Admur in the Siddur, as well as the other Poskim listed above, take the approach that it refers to the braid and below the braid. In the Shulchan Aruch however Admur takes the last approach, as will be explained.
 Admur ibid; Rav in Menachos ibid
 Admur 8:13; Siddur Admur; Taz 8:8; Poskim ibid and in addition so also rule: Kitzur SHU”A 9:13; M”B 8:21; Biur Halacha 12:1 “Yeish Lismoch”; Tehila Ledavid 12:2; Chazon Ish 3:6; Kaf Hachaim 8:37; See Piskeiy Teshuvos 12:3
The reason: As when the tear occurs beneath the Gdil, by the holes, it is considered as if both sides have been cut off, and hence an entire string is missing. [Tehila Ledavid ibid]
 Siddur Admur; Shlah Chulin 112a in interpretation of Rav in Menachos 39a; Elya Raba 8:10 in name of Taz and Shlah; Emek Haberacha 2:13; Soles Belula 12:2
The reason: As whenever it tears beneath the Anaf, it is viewed that the entire string has torn and one hence only has three whole strings remaining. [Shalah ibid]
Ruling of Admur in Shulchan Aruch and other Poskim: In the Shulchan Aruch 12:6 Admur rules that only when a string requires a minimum length of 4 cm, is there a difference of opinion regarding if the string tore in the braided area. This implies that if the string does not require 4 cm, such as if the other side of the string still maintains a 4 cm length, then according to all [even Rashi] it does not invalidate the Tzitzis even if it tore within the braid. So rules also Biur Halacha 12:1 “Yeish Lismoch”; Kitzur SHU”A 9:13; Tehila Ledavid 12:2. This is all regarding if the tear occurred within the Gedil. If however the tear occurred below the Gedil, by the hole, then it is invalid according to all. [Admur 8:13; Poskim ibid]
Ruling of Mishneh Berurah: In Biur Halacha ibid, the M”B rules that if the tear occurred within the first set of loops, it is invalid. If it occurred after the first two knots made on top of the first set of loops, and there is 4 cm of string that protrudes, it is valid. [See Piskeiy Teshuvos ibid]
 As the last two knots are still considered part of the Gdil from which the Anaf extends, and hence when a tear occurs in that area, the Anaf is considered to have lost one whole string.
 As the knots separate between the Anaf and the Gedil, and hence if the string is now extending from beneath the knots, within the Gedil, it is now invalid as it is considered as if its root is torn, and hence both sides are now considered torn. However, according to this understanding, even if a string did not tear but simply unraveled from the knots, and now extends below the knots, it would be invalid, and this is preposterous to even ponder.
 Admur 12:2; Siddur Admur; Michaber 12:1 [Up to four strings from one side may tear completely]
 The reason: As Tzitzis can only become invalid due to a tear, if an entire one of the four long strings is torn. Hence, when only one of the 8 strings tore, the Tzitzis is always valid, as the other side of that string is still intact, and hence there still remain 4 long strings. [Admur 12:2]
 12:2 and 3; Siddur Admur
 The reason: As Biblically, Tzitzis requires 4 strings, and when one of these strings has been cut off from each of its two sides, it is considered completely missing. [12:2]
 What is Kdei Aniva? Some Poskim say this means that there is enough length left of the string for it to make three knots on a single string. [1st opinion in Admur 12:1; M”A 12:2] Other Poskim however rule this means that there is enough length left of the string for it to make even a single knot on all the strings together. [2nd opinion in Admur ibid; Michaber 12:1] Meaning, that there is enough length for one to gather all the torn strings and then make a single knot over them. [M”B 12:1] Practically, one is to be stringent like the first opinion. [Admur ibid; M”A ibid]
If the strings are thick: In all cases that Kdei Aniva is required and due to the thickness of the string one is unable to make the required knots, then the string is valid if it would be able to make the required knots if it were of average thickness. The reason is as follows: If this string would be Kosher even if it were less thick, being that it can make the required knots, then certainly when it is more thick and hence more recognizable, it should not be invalidated. [12:5; Michaber:Rama 12:2]
Is Kdei Aniva Biblically or Rabbinically required? Some Poskim rule it is Biblically required. [Chazon Ish 3:15] Others rule it is Rabbinically required, as Biblically even a small amount suffices. [Rav Akiva Eiger 12; Levush 12:1]
 Shiurei Torah p. 274 based on his personal measurement; See also Biur Halacha 12 “Im Nifsiku” that “certainly one is not to be stringent on more than 2 Gudlin”.
Other opinions: Some Poskim rule Kdei Aniva is 4 Gudlin, which is 8 cm. [Kitzur SHU”A 9:13; Siddur Yaavetz; Chayeh Adam brought in Biur Halacha] The Biur Halacha negates this opinion. Others write the measurement is 2 2:3 Gudlin, which is 5.3 cm. [brought in Kaf Hachaim 12:1] Others write it is 2.65 cm [Toras Chaim Sofer 12:3] According to the Chazon Ish it is 5 cm.
 Implication of Siddur Admur; first opinion and custom in Admur 12:6 and Michaber 12:3
Meaning that one measures the 4 cm beginning from after the last knots of the braid, starting from where the strings hang loose [Anaf], and the braided area does not count at all for this measurement.
Including the braided area within the Kdei Aniva measurement: In the Shulchan Aruch 12:6 Admur records two opinions regarding from where one measures Kdei Aniva; is it from the Anaf or from the Gdil? Some Poskim rule that the Kdei Aniva is measured from after the Gdil, meaning that the entire braid must remain whole, and from the last knot extends Kdei Aniva of the torn string. [1st opinion in Admur and Michaber ibid; Rashi as explained in Tosafus Menachos 38b] Others however rule that it is measured beginning from the bottom of the braid, and hence even if the string tore within the braid, if there is a measurement of Kdei Aniva from there until the hole in the corner, it is valid. [2nd opinion in Admur and Michaber ibid; Riy in Tosafus Menachos 38b; Rosh 7] Practically, the worldly custom is like the first opinion, to require Kdei Aniva from the Anaf that extends past the Gdil, however in a case of need, such as when one does not have other Tzitzis available, one may rely on the 2nd opinion. [Admur ibid; Michaber ibid] Nevertheless, one is not to say a blessing on such Tzitzis, as Safek Brachos Lihakel. Likewise, one is not to wear such Tzitzis in a Reshus Harabim on Shabbos. [Admur ibid; M”A 12:7] However, one may continue to wear the Tzitzis. [Tehila Ledavid 15:3] See P”M 12 A”A 7; Hisorerus Teshuvah 1:3 regarding why one may continue wearing it [and nullify a positive command] but may not say a blessing. The P”M ibid explains that when Tzitzis are not available it is permitted to wear a Tallis without Tzitzis.
Ruling of Siddur-The law if no other Tzitzis are available: As stated above, Admur in the Shulchan Aruch rules that if there are no other Tzitzis available one may be lenient to wear a Tallis that has two torn strings which only measure Kdei Aniva from the first knot. The question is hence asked if this ruling holds true according to Admur in the Siddur, and one would hence be allowed to continue wearing Tzitzis with two strings completely torn until the knots, until new Tzitzis become available. The following is the argument to say that according to the Siddur it is forbidden to do so: 1) According to the Siddur, if even one string tore in the Gdil, the Tzitzis is invalid. This shows that according to the Siddur the Gdil is considered the root of the Tzitzis, and even the Riy agrees that the root of the Tzitzis [below the knots] is not included in Kdei Aniva, and hence according to Admur’s understanding of the term “root”, according to all Kdei Aniva must be measured from above the braid. 2) Admur writes in the Siddur that if “both strings are less than Kdei Aniva [4 cm], it is invalid”. This must be referring to a case that the strings tore above the braid, as otherwise even one torn string would be invalid. Now, why does Admur state it is invalid if according to the Riy it still contains Kdei Aniva, being we include the braid in the measurement, as Admur brings in 12:6. One must thus conclude that in the Siddur Admur rules completely like Rashi and hence cannot be lenient at all like the Riy even if no other Tzitzis are available. Rav D.B. Levin however stated to me that in his understanding, even according to Admur in the Siddur one is to follow the above conclusion to wear the Tzitzis if no other Tzitzis are available, being that whenever Tzitzis are not available there is no Biblical prohibition involved in wearing a Tallis without Tzitzis [M”A 13:8; P”M 12 A”A 7], and hence regarding the Rabbinical prohibition one can rely on the opinion of the Riy, even according to the Siddur, as even the Siddur agrees that in such a case one benefits the Mitzvah according to the Riy, and hence there is no prohibition to do so. However, in my opinion this is not correct as a) There is a Rabbinical prohibition involved even when Tzitzis are not available, and if Admur holds that the Tzitzis are invalid [and not just a dispute] then there is no allowance to wear it and transgress a Rabbinical prohibition. B) It is implied from Admur 13:6 that he holds like those Poskim who rule that even when Tzitzis are not available the Biblical prohibition remains [Elya Raba 13:6; Mamar Mordechai 13:5; Taz 13:5] and hence being in the Siddur he rules plainly like Rashi and does not even mention the Riy, there is thus no allowance to be lenient even when no other Tzitzis are available.
 The reason: The reason for this is because in the times of Techeles, two of the four long strings were the white strings, and two of the four strings were Techeiles. Now, although today we no longer have Techeiles, nevertheless we still take another two white strings in place of the Techeiles, for a total of four white strings. However, there still remains a Halachic difference between the two original white strings and the two additional white strings taken in place of the Techeiles. The difference is as follows: The two original white strings must always maintain their minimum length of 12 Gudlin on each side, while the other two white strings, since they are a mere replacement for the Techeiles, are valid even they tear, so long as Kdei Aniva remains on at least one side. This is because since at the time that these two strings were placed on the corner they were whole, therefore a later tear does not invalidate them to serve as replacement of the two Techeiles strings. However the original two long strings which are the main aspect of the Mitzvah, and had to be around even in the times of Techeiles, must always be whole [12 Gudlin], in which case they then have the power to validate the Tzitzis even if the other two strings tore, so long as each one maintains Kdei Aniva on at least one side. [Admur 12:3 in explanation of opinion of Rabbeinu Tam; based on Levush 12, and so rules Admur in Siddur; See D in footnotes for the other opinion in Shulchan Aruch]
 The reason: As in such a case it is possible that one of the 4 original strings is entirely missing [in the Anaf area] and is thus Biblically invalid. [ibid]
 If neither side of the torn string alone contains Kdei Aniva [4 cm] it is nevertheless invalid even if it contains the length of Kdei Aniva when combined with the other torn string [i.e. each string has 3 cm left for a combination of 6 cm]. Now, although in such a case it is found that even if both tears belong to the two ends of the same long string, the long string still contains Kdei Aniva, nevertheless, since the head of each side of this string that extends past the knot does not contain Kdei Aniva, it is therefore considered non-existent. As whenever a string has been cut to below Kdei Aniva [4 cm] it is considered as if it is completely missing, and hence it is as if there is nothing left of one of the four long strings. [ibid]
 Michaber 12:1
 Michaber 12:3; Admur 12:6; M”A 12:7; Tehila Ledavid 15:3
 As in such a case we rely on the opinion of the Riy that states we include the braided area within the measurement of Kdei Aniva [Michaber 12:3; Admur 12:6; M”A 12:7], and hence in this case since the entire braid still remains of each of the torn strings, they both still contain Kdei Aniva according to the Riy.
 See previous footnote under “Ruling of Siddur-The law if no other Tzitzis are available” for the full analysis of this matter, and the opinion of Rav S.D. Levin that the allowance applies even according to the Siddur.
 Shaareiy Teshuvah 12:2
 Artzos Hachaim; See Pischeiy Teshuvah 12
 Siddur Admur; Opinion of Rabbeinu Tam brought in Admur 12:3 and Michaber 12:1; Rama 12:1 “so is custom”
Ruling of Admur in Shulchan Aruch and other opinions:
In the Shulchan Aruch [Michaber 12:1; Admur 12:1-4] a dispute is recorded in this matter.
First opinion: Some Poskim rule that a Tzitzis remains Kosher even if all eight strings tore, so long as Kdei Aniva remains on each of the four long strings. This means as follows: If all eight strings tore but each of the eight strings still maintains a length of Kdei Aniva, the Tzitzis is valid. [12:1; The same would apply even if one of the eight strings completely tore, being that its other side conations Kdei Aniva.] Furthermore, if one verified to keep the sides separate throughout the tying, and four strings of one side completely tore until nothing remains, then if the four strings of the other side maintain a length of Kdei Aniva, it remains valid. Meaning, even if all eight strings tore, and the four strings of one side tore completely and the four strings of the other side all retain Kdei Aniva, it is valid. The reason for this is because each of the four long strings still maintains a length of Kdei Aniva on at least one side. If however two strings tore to less than Kdei Aniva on opposite sides, or on the same side and one was not careful to separate the sides during tying, then the Tzitzis is invalid, as in such a case perhaps one of the four long strings have completely torn. [12:2; first opinion in Michaber ibid; opinion of Rosh in Menachos 38] According to this opinion, some opinions hold it is valid even if all eight strings tore within the Gdil, as explained in previous footnotes. [see 12:6]
Second opinion: Other Poskim [Rabbeinu Tam] however rule that the Tzitzis only remains Kosher after the tearing of strings if at least two of the four long strings maintain the initial minimum length of 12 Gudlin. This means that each side of the string must have a minimum length of 12 Gudlin from the first knot near the corner. If however three of the four long strings no longer contain a minimum length of 12 Gudlin on each side, it is invalid. This applies even though they still maintain a length of Kdei Aniva. [see the reason mentioned below] For this reason, if three of the 8 strings tore [to below 24 cm] then even if they maintain a length of Kdei Aniva, it is nevertheless invalid, as perhaps each one of these torn strings belongs to a different one of the four long strings, and it is hence found that only one of the long strings is still whole [12 Gudlin] on each side.[Admur 12:3 and Michaber 12:1]
Final Ruling of Admur in Shulchan Aruch and other Poskim: The custom is to be stringent like the second opinion [Admur ibid; Rama ibid] however in a time of need, such as other strings are not available, one may rely on the first opinion [that it is valid even if all the strings are less than 24 cm, so long as four strings maintain Kdei Aniva on one side] being that so is the main Halachic opinion. [Admur ibid; Michaber ibid] One may wear such Tzitzis even with a blessing. [implication of M”A 12:7 and P”M 12 A”A 7; M”B 12:11; Biur Halacha “Vehalacha” Ketzos Hashulchan 7 footnote 55] Others however argue that a blessing may not be recited. [Chayeh Adam 11:20; Even Yisrael 9:3]
 Admur 12:3; As explained in Halacha 5 that 12 Gudlin is the minimum length of a string
Other opinions: Some Poskim rule that according to all the strings remain valid if they retain a minimum length of one Tefach, which is four Gudlin. [Chazon Ish 3:6 based on first opinion in Michaber second Michaber 8:4; See also Artzos Hachaim 12:1 and 17]
 As explained in Halacha 5
 The reason: The reason for this is because in the times of Ticheles, two of the four long strings were the white strings, and two of the four strings were Techeiles. Now, although today we no longer have Techeiles, nevertheless we still take another two white strings in place of the Techeiles, for a total of four white strings. However, there still remains a Halachic difference between the two original white strings and the two additional white strings taken in place of the Techeiles. The difference is as follows: The two original white strings must always maintain their minimum length of 12 Gudlin on each side, while the other two white strings, since they are a mere replacement for the Techeiles, are valid even if they tear, so long as Kdei Aniva remains on at least one side. This is because since at the time that these two strings were placed on the corner they were whole, therefore a later tear does not invalidate them to serve as replacement of the two Techeiles strings. However, the original two long strings which are the main aspect of the Mitzvah, and had to be around even in the times of Techeiles, must always be whole [12 Gudlin], in which case they then have the power to validate the Tzitzis even if the other two strings tore, so long as each one maintains Kdei Aniva on at least one side. [Admur 12:3 based on Levush 12]
 Rama ibid; If three tore from the same side, and one was careful to keep the sides separate throughout the tying, then one knows for certain that three of the four long strings are no longer whole. If they tore on different sides, or one was not careful in the above, then although it is only a doubt as to whether three of the four strings are no longer whole, it is nevertheless invalid. [ibid]
Made signs on the strings: In the event that one made a sign on each one of the eight strings [such as the tips of each end have matching colors, string 1 is blue on both ends; string 2 is yellow on both ends etc] and hence knows which side each string belongs to, then the Tzitzis is Kosher even if four strings tear below 24 cm [but maintain Kdei Aniva] if one sees that the four remaining strings are each other’s pairs. [M”A 12:5; see Machatzis Hashekel ibid]
 Tehila Ledavid 11:10
 P”M 12; Rav Akiva Eiger; See Biur Halacha 12 “Yeish Lismoch”; Tehila Ledavid 12:5
 Beir Heiytiv 12:6 in name of Halachos Ketanos 2:112
 See Admur 10:12; 15:8; above Halacha 7C
Other opinions: Some Poskim rule that one must undo all the other Tzitzis when replacing an invalid Tzitzis. [Levush brought in M”A ibid]