Quenya 

tam-

verb. to tap

tam- vb. "to tap" (1st pers. aorist tamin "I tap"), pa.t. tamnë (TAM)

tambë

copper

tambë (2) noun "copper" (LT1:250; this is "Qenya"; see urus for a later word for "copper")

tampë

copper

tampë noun "copper" (LT1:268; in LotR-style Quenya tampë is [also?] the past tense of tap- "stop, block")

urus

noun. copper

A noun for “copper” in notes from the late 1960s based on the root √(u)rus (VT41/10).

Conceptual Development: The Qenya Lexicon of the 1910s had ᴱQ. tambe “copper, bronze” under the early root ᴱ√TAMA “beat; smelt, forge” in the contemporaneous Qenya Lexicon (QL/88).

Neo-Quenya: For purposes of Neo-Quenya, I would retain ᴺQ. tambë with the meaning of “bronze”, but would use the later word urus for “copper”.

pet-

verb. knock, strike

#pet- vb. "knock, strike" (cited as "pete", perhaps with a suffixed stem-vowel); pa.t. pentë given. (QL:73)

urus

copper

urus (urust-) noun "copper" (VT41:10)