NAIL. Six different words are used in the Bible for nails.
1. טְפַר, H10303, the claw of birds or animals. It is used to describe Nebuchadnezzar’s appearance in his madness (Dan 4:33) and the iron claws of the fourth beast in Daniel’s vision (7:19).
2. צִפֹּ֫רֶן, H7632, finger or toe nails. The Oriental women in time of mourning let their persons go uncared for, sometimes as long as a year. The end of mourning was marked by dressing the hair and cutting the nails. The captive woman is given a month to mourn her separation from her people (Deut 21:12). Then to indicate the end of her mourning, and perhaps the putting off of her heathenism, she cuts her nails, grooms herself and joins the community of Israel.
3. יָתֵד, H3845, is actually a wooden peg or stake. Used as a tent peg, the sharpened stick was a lethal weapon in the hands of Jael (Judg 4:21, 22). Such pegs were driven into the walls of houses and used as hangers for various articles. It is used as a symbol of security and dependability, either of a man (Zech 10:4) or of a wise saying (Eccl 12:11). Ezra 9:8 even likens God’s grace to such a “nail.”
4. מַשְׂמְרֹ֥ות, מַסְמֵר, H5021, are the nails of the carpenter and cabinet maker. Widely used from ancient times they differ little in size and shape from those used today. Made usually of bronze or iron, they were hand forged and tapered more gradually than the machined nails of today. Nails with gold or silver heads have been found that were used for decorative purposes. Scripture speaks of the great abundance of nails prepared for the erection of the Temple (1 Chron 22:3; 2 Chron 3:9).
5. ̔Ηλος. Iron spikes such as were used in the crucifixion of Jesus have been found dating to Rom. times (John 20:25; Col 2:14).
International Standard Bible Encyclopedia (1915)
In a figurative sense the word is used of the hard point of a stylus or engraving tool: "The sin of Judah is written with a pen of iron, and with the point (literally, "claw," "nail") of a diamond: it is graven upon the tablet of their heart, and upon the horns of your altars" (Jer 17:1).