Zi Collection, Page Position: Upper, Radical: Horse (mǎ), Page 124, Entry 07
Pronounced sou (low tone)
From the "Guangyun" (Guangyun): The pronunciation is suō jiū qiè. From the "Jiyun" (Jiyun) and "Zhengyun" (Zhengyun): The pronunciation is shū jiū qiè. The sound is the same as "sōu". The "Jiyun" explains it as to engrave or carve. The "Erya·Shiqi" (Erya·Shiqi) states: "To engrave is called lòu suō". The commentary says: To engrave objects is called suō. The "Shiwen" (Shiwen) marks the pronunciation of suō as sū lóu fǎn.
Note: The "Guangyun" states it is a decoration on a horse's head, which is actually the explanation for the character "鋄". This is now deleted.
Additionally, from the "Jiyun": There is also a pronunciation of shuāng qū qiè, with the sound the same as "shū". The meaning is the same. The "Zhengyun" also writes it as "鎪".