Are there any halachot regarding the "atzei chayim" (wooden poles) placed on a Torah scroll?

Question

Are there any halachot regarding the poles used on the sides of a Torah scroll? For example:

• All the poles that I have seen are made from wood. Must they be made from wood or can any materials whatsoever, be used? If not, what factors would restrict the materials allowed?
• Do the poles need to be a minimum or maximum height and thickness?
• Is there a minimum distance between the ends of the parchment / writing on both sides of the Torah scroll that these poles must be placed?
• Does the parchment need to be sewed into the wood or can it be glued, tacked, or stapled?

Fee free to add any other halachot that may be appropriate. Most importantly, if there is a condensed source dealing with all the laws, please refer and / or link.

Answer 1

The Shulchan Aruch in Yoreh Deah סימן רעח - דין תפירת ספר תורה says:

ב: יָשִׂים בַּסֵפֶר תּוֹרָה שְׁנֵי עַמּוּדִים, אֶחָד בְּרֹאשׁוֹ וְאֶחָד בְּסוֹפוֹ, וּמַה שֶׁשִּׁיֵּר גִּלָּיוֹן בְּרֹאשׁוֹ וּבְסוֹפוֹ יִכְרֹךְ עַל הָעֲמוּדִים וְיִתְפְּרֶנּוּ (ב) בְּגִידִים, וְיִשָּׁאֵר בֵּין הָעַמּוּד לַדַּף שְׁתֵּי אֶצְבָּעוֹת. _{וּבִשְׁעַת הַדַּחַק, שֶׁאִי אֶפְשָׁר לְתָפְרָהּ בְּגִידִין, אִם נִתְפְּרָה (ג) בְּמֶשִׁי סְבִיב הָעַמּוּדִים, קוֹרִין בָּהּ. מִיהוּ אִם אֶפְשָׁר לְתַקְּנָהּ בְּגִידִין, אַף עַל פִּי שֶׁכְּבָר נִתְפְּרָה בְּמֶשִׁי, אֵין קוֹרִין בָּהּ עַד שֶׁיְּתַקְּנֶנָּה (ת''ה סי' נ''א) .‏}

The Be'er Heitev adds:

באר היטב (ב) בגידים. אבל אסור לדבק היריעות בדבק סביב העמודים כי בימים רבים מתייבש הדבק ומתרפה מעל העמודים כ''כ מהרי''ו ובד''מ מסיים בשמו מיהו בשעת הדחק שרי ולא נמצא כן במהרי''ו שם עכ''ל הש''ך: (ג) במשי. וה''ה בין היריעות כן הוא בת''ה שם ומוכח שם להדיא דכ''ש אם נתפר במשי במקום הקרע שכשר בשעת הדחק עכ''ל נה''כ: ‏

So, to answer your questions:

All the poles that I have seen are made from wood. Must they be made from wood or can any materials whatsoever, be used? If not, what factors would restrict the materials allowed?

It seems that any material is allowed, as none is specified. However, I suspect that wood is usually used, in tribute to the verse (Mishlei 3:18) עֵץ חַיִּים הִיא לַמַּחֲזִיקִים בָּהּ - and they are typically called the עצי חיים.

Do the poles need to be a minimum or maximum height and thickness?

Doesn't say, but it has to be long and strong enough to handle Hagbah.(Source: Common sense.)

Is there a minimum distance between the ends of the parchment / writing on both sides of the Torah scroll that these poles must be placed?

Yes. Two fingers between the end of the writing and the part wrapped around the pole.

Does the parchment need to be sewed into the wood or can it be glued, tacked, or stapled?

Must be sewn - preferably with Gidin (sinews), like the rest of the Sefer Torah, but in a pinch silk (or other threads) can be used, temporarily.

Gluing it is forbidden as it can dry with age and fall off, but in emergency some allow it as a temporary solution.

Stapling or tacking it on would be like using silk, I imagine, and can be temporarily used in emergency.