Perhaps from the root of Birzowth; iron (as cutting); by extension, an iron implement -- (ax) head, iron.
see HEBREW Birzowth
H1270. barzel
בַּרְזֶל noun masculineDeuteronomy 19:5 iron (with ל afform.; from piercing ? Late Hebrew id., Aramaic id., מַּדְזֶל, , Phoenician ברזל, Assyrian parzillu COTGloss, (Arabic fetter is loan-word)) — always absolute ׳ב Genesis 4:22 74t. (בַּרְזֶל֑ 4:22 etc.); —
1 iron, literally:
a. iron-ore, stone containing iron, Deuteronomy 8:9; Job 28:2;
b. as raw material (to be worked) Genesis 4:22; 1 Chronicles 22:3, 14, 16; 29:2 (twice in verse); 29:7; 2 Chronicles 2:6; 2:13; 24:12; Isaiah 44:12;
c. as article of commerce Ezekiel 27:12, 19;
d. as material of furniture, utensils, implements, etc., ב ׳עֶרֶשׂ Deuteronomy 3:11, ב ׳רֶכֶב Joshua 17:16, 18; Judges 1:19; 4:3, 13, ב ׳כְּלֵי Joshua 6:19, 24 compare 1 Kings 6:7; Numbers 35:16, ׳עֵטבֿ Job 19:24 & figurative Jeremiah 17:1, הַבּ ׳חֲרִצֵי 2 Samuel 12:31= 1 Chronicles 20:3, הַבּ ׳מַגְזְרוֺת 2 Samuel 12:31 cutting instrument of iron, see Amos 1:3, ב ׳כַּבְלֵי Psalm 149:8 ("" זִקִּיִם), ב ׳נֵשֶׁק Job 20:24, ב ׳קַרְנֵי 1 Kings 22:11 2 Chronicles 18:10, ב ׳קִיר & ב ׳מַחֲבַת Ezekiel 4:3; ב ׳בְּרִיחֵי, i.e. of Babylon, ag. Cyrus Isaiah 45:2; compare 1 Samuel 17:7 & Isaiah 60:17 (twice in verse) (figurative)
2 tool of iron Deuteronomy 27:5; Joshua 8:31; Proverbs 27:17 (twice in verse); Ecclesiastes 10:10; Isaiah 10:34 (metaphor); head of an axe Deuteronomy 19:5; 2 Kings 6:5-6, so weapon 2 Samuel 23:7; Job 41:19; compare also Numbers 31:22; Joshua 22:8 where iron as spoil of war.
3 iron in figure of unwatered earth Deuteronomy 28:23; of Egyptian bondage, הַבּ ׳כּוּר 4:20; 1 Kings 8:51; Jeremiah 11:4; of oppression ב ׳עֹל Deuteronomy 28:48; Jeremiah 28:14 compare 28:13; of strength 15:12 (twice in verse); compare ׳ב מִנְעָלֶיךָ Deuteronomy 33:25 & Micah 4:13 ב ׳קֶרֶן; of prophet, firm through Yahweh's might, ׳ב עַמּוּד Jeremiah 1:18; of distress, ב ׳בְּרִיחֵי Psalm 107:16 compare 107:10 of judgments of ׳י, & 105:18; ב ׳שֵׁבֶט 2:9; of evil-doers, Jeremiah 6:28; Ezekiel 22:18, 20; simile of scorching sky Leviticus 26:19; ב ׳מְטִיל of bones of hippopotamus Job 40:18; ב ׳גִּיד of obstinate neck of Israel Isaiah 48:4.