Reference for Kelim 16:1
כָּל כְּלִי עֵץ שֶׁנֶּחֱלַק לִשְׁנַיִם, טָהוֹר, חוּץ מִשֻּׁלְחָן הַכָּפוּל, וְתַמְחוּי הַמִּזְנוֹן, וְהָאֱפִיפוֹרִין שֶׁל בַּעֲלֵי הַבָּיִת. רַבִּי יְהוּדָה אוֹמֵר, אַף הַמָּגֵס, וְקוֹד הַבַּבְלִי כַּיּוֹצֵא בָהֶן. כְּלֵי עֵץ, מֵאֵימָתַי מְקַבְּלִין טֻמְאָה. הַמִּטָּה וְהָעֲרִיסָה, מִשֶּׁיְּשׁוּפֵם בְּעוֹר הַדָּג. גָּמַר שֶׁלֹּא לָשׁוּף, טְמֵאָה. רַבִּי מֵאִיר אוֹמֵר, הַמִּטָּה, מִשֶּׁיְּסָרֵג בָּהּ שְׁלֹשָׁה בָתִּים:
A wooden vessel that was broken into two becomes clean, except for a folding table, a dish with compartments for [different kinds of] food, and a householder's footstool. Rabbi Yehudah says: also a double dish and a Babylonian drinking vessel are the same. When do wooden vessels begin to be susceptible to impurity? A bed and a cot, after they are sanded with fish skin. If the owner determined not to sand them they are susceptible to impurity. Rabbi Meir says: a bed [becomes susceptible to impurity] when he knits three rows of meshes.