The name as it now stands has no proper translation. It appears in Ezekiel 27:13, as the name of a tribe or clan. There is a possibility that the word is related to the Persian TU-PHAL = dross of metal. Thus the combined letters would imply a 'worker in metals.'" ("Ars Quatuor Coronatorum," 97 (1984): 77).
I find in Gesenius Lexicon of the Hebrew/Chaldee Old Testament that "תּוּבַל קַיִן (perhaps “smith of scoria,” compare of Arab. قَيْنُ smith, and Pers. توبل scoria of metal, the genitive being put first, which seems to shew the origin to be Assyrian or Persic [but be it remembered that it is an antediluvian proper noun]), Tubalcain, proper noun of a son of Lamech, inventor of working in iron, Gen. 4:22." (p. 858)
I also find in the HALOT (Hebrew, Aramaic Lexicon of the Old Testament) this: "Miller in ZAW 86 (1974) 168f, who takes תּוּבַל as being the name of a territory תֻּבַל which is to be identified with Akkadian Tabāl. קַיִן becomes associated with it through the tribe of the Kenites, smiths who felt they were to be grouped with the Israelites." (p. 1694).
John Skinner in his book "Genesis," (The International Critical Commentary, latest impression, 1980: 119, in note on bottom of the page) noted that the possibilities of being a "hammerer" of metals, as in an instructor, or else "A hammerer of every cutting implement of..." are interesting, though he thinks ultimately unsatisfactory.
The "Interpreter's Dictionary of the Bible" indicates the name functions as an eponymous ancestor of all metal-smiths, and also notes that Mowinckel "interprets tubal as 'one who brings forth, produces property.'" (4 vols., Abingdon Press, 1962, quote in Vol. 4:718)
In "Mackey's Revised Encyclopedia of Masonry," we read that the T and Baal are combined hence possibly indicating the meaning "the lord Cain. Again dhu, or du in Arabic signifies Lord and there are interchangeable forms of Du, Tu, and Di in many Semitic words. Tubal Cain has ultimately been shown to be Semitic, and Vulcan to be Aryan, following Mackay. The Sanskrit 'ulka' means a firebrand, hence we get the Latin 'fulgar,' and 'fulme,' which are names of the lightning. Why it is adapted into Masonic craft is due to him representing the labor to acquire truth, and not worldly possessions. (Vol. 2:1060).
More interesting still is Harry Carr's analysis in his book "The Freemason at Work," Privately Printed, London, 1976: 170, wherein he noted that Tubal-Cain foreshadows Hiram Abif, who is also declared to have the same skills as Tubal-Cain. Genesis 4:22 uses the precise same Hebrew words as does 1 Kings 7:14 to describe both men in their craft as
The BDB (Brown, Driver, Briggs Lexicon of the Hebrew Old Testament), noted that the Hebrew here can mean "engrave," or to "plow." חֲרַת engrave, ܚܪܰܬ (ḥrat) cleave, plough, Arabic حَرَثَ (ḥaraṯa) plough) The Hebrew חָרָשׁ "harash" means graver, artificer: worker in metal 1 Samuel 13:19; Hosea 8:6; 13:2; Deuteronomy 27:15; Jeremiah 10:9. Can also mean a worker in stone, or an engraver of gems. (360:1)
Carr's point about Tubal Cain and Hiram Abif is that "Tubal Cain was the founder of the craft in which H.A. above all, excelled and he was the direct link between the two earliest pillars and those of Solomon's Temple."