{{Short description|Copper-zinc alloy}} {{use dmy dates|date=May 2026}} {{Distinguish|Tombak (disambiguation)|Tumbaga}} [[Image:Tombac ewer.JPG|thumbnail|Ottoman tombac ewer and basin set – 1870 – Collection of Turkish and Islamic Arts Museum – Brought to museum in 1926 from the tomb of Sultana Pertevniyal]] {{Multiple issues| {{refimprove|date=May 2026}} {{update|date=May 2026}} {{lead rewrite|reason=it violates WP:LEAD and WP:VERIFY, in presenting novel material rather than an article summary, and in presenting facts not clearly supported by available sources|date=May 2026}} }} '''Tombac''', or '''tombak''', is a brass alloy with high copper content and 5–20% zinc content.{{citation needed lead|date=May 2026}}<!--The following is a commercial metal sales site, and not a reliable source for this type of academic metallurgical information:<ref name="market-metal.com">{{cite web |url=http://www.market-metal.com/reviews/reviews_175 |title=Buy silicon wafers, copper, aluminium, tantal, niobium and stainless steel. Export of non-ferrous and precious metals, London metal exchange (LME) prices |accessdate=2009-08-02 |url-status=dead |archiveurl=https://web.archive.org/web/20090903084343/http://www.market-metal.com/reviews/reviews_175 |archivedate=2009-09-03 }}</ref>--> Tin, lead or arsenic may be added for colouration.<ref>{{cite journal| author = Unstated. |date = 1930 | title = Unstated title. | journal = Journal of the Institute of Metals | volume = 43 | issue = | page = Unstated issue, pg. nos. | url = | access-date = }}{{failed verification|date=May 2026}}</ref>{{failed verification|date=May 2026}}{{Request quotation|date=May 2026}}<ref>{{Cite web|url=http://www.schlenk.de/index.php?id=519&L=1&kat=1.1.1#719|title = SCHLENK AG: Automotive refinish coatings}}{{dead link|date=May 2026}}{{failed verification|date=May 2026}}</ref>{{dead link|date=May 2026}}{{failed verification|date=May 2026}} It is a cheap malleable alloy mainly used for medals, ornament, decoration and some munitions.{{citation needed lead|date=May 2026}} <!--Out until quote is provided, and the fact is elsewhere substantiated, because conflicts with article content: "In older use,"-->The term may apply to brass alloy with higher zinc content.<!--Out until quote is provided, and the fact is elsewhere substantiated, because conflicts with article content: "as high as 28–35%".--><ref>{{cite book| author = Singer, T.E.R. | date = 1945 | chapter = Unspecified entry. | title = German-English Dictionary of Metallurgy: With Related Material on Ores, Mining and Minerals, Crystallography, Welding, Metal-working, Tools, Metal Products, and Metal Chemistry | page = unstated. | location = New York, NY | publisher = McGraw-Hill | isbn = | url = https://books.google.com/books?id=_VSFAAAAIAAJ | access-date = 2026-05-13 }}{{failed verification|date=May 2026}} Note, no book content is available at this web link.</ref>{{failed verification|date=May 2026}}{{Request quotation|date=May 2026}}<!--A commercial metal sales site, and not a reliable source for this type of academic mettalurgical information:<ref name="market-metal.com"/>-->
==Etymology== {{unreferenced section|date=May 2026}} The term ''tombak'' is derived from ''tembaga'', an Indonesian/Malay word of Javanese origin meaning 'copper'.{{citation needed|date=April 2014}} ''Tembaga'' entered Dutch usage concurrent with their colonisation of Indonesia. Likely, the term was used generically to describe Indonesian high-copper brass items, including gamelan gongs. It is one of the very few Indonesian loan words used in English or German.
==Common types== {{multiple issues|section=yes| {{one source|date=May 2026}} {{update|section|date=May 2026}} {{refimprove section|date=May 2026}} }} Andrew Ure, writing in the late 19th century, and summarising with regard to "''Tomba[c]'', or red brass", states that "in the cast state, [it] is an alloy of copper and zinc, containing not more than 20 per cent of the latter constituent."<ref name=Ure1856>{{Cite book |last=Ure |first=Andrew | author-link = Andrew Ure | date = 1856 | title=A Dictionary of Arts, Manufactures, and Mines: Containing a Clear Exposition of Their Principles and Practice | editor = Hunt, Robert | volume = I | pages = 47, 239, 243f | location = New York, NY | publisher= D. Appleton & Co. | url= https://archive.org/details/dictionaryofart01urea/page/239/mode/1up?q=tombak | access-date = 2026-05-13 | via = }}</ref>{{rp|p. 243}} He notes that the specific gravity of brass, in general, is "greater than the mean density of its constituents, varying from 7.82 to 8.73, according to the proportion of zinc and copper".<ref name=Ure1856/>{{rp|pp. 243f}} He goes on to note, with regard to tombac in particular—which he uniformly spells as "tombak" (as will thus appear in his quotations)—that its specific gravities are yet higher, with "sheet tombak (81.25 copper + 18.75 zinc) [being] 8.788" and that "tombak wire (87.5 copper + 12.5 zinc) has been found so great as 9.00".<ref name=Ure1856/>{{rp|p. 244}}
On publishing his ''A dictionary of the Arts, Manufactures, and Mines'' in England in 1839, and republishing in the U.S. 1856, Ure noted that,<blockquote>"Red brass, the Tombak of some... consists of more copper and less zinc, than go to the composition of [yellow] brass [at 70 copper, 30 zinc<ref name=Ure1856/>{{rp|p. 243}}]; [Tombak] being from 2½ to 8 or 10 of the former [copper] to 1 of the latter [zinc]. At the famous brass works of Hegermühl... 11 parts of copper are allowed with 2 of zinc into red brass, from which plates are made that are afterward rolled into sheets. From such an alloy the Dutch foil, as it is called, is manufactured at Nürnberg; Pinchbeek, Similor, Mannheim gold, are merely different names of alloy similar to Prince's metal. The last consists of 3 of copper and 1 of zinc, separately melted, and suddenly incorporated by stirring.<ref>{{Cite book |last=Ure |first=Andrew | author-link = Andrew Ure | date = 1839 | title=A Dictionary of Arts, Manufactures, and Mines: Containing a Clear Exposition of Their Principles and Practice | edition = first, illustrated | pages = 30, 165, 1258 | location = London, England | publisher= Longman, Orme, Brown, Greene, & Longmans | url=http://archive.org/details/b2930345x | access-date = 2026-05-13 | via = Welcome Library}}</ref>{{rp|p. 165}}<ref name=Ure1856/>{{rp|p. 239}}</blockquote>
A.S. Piggot, writing in 1858, offered a distinct definition of tombac (likewise using the varian "k" spelling), and perhaps drawing from Ure, stated that:<blockquote>''Red brass'', or ''tombak'', as it is called by some, has a great preponderance of copper, from 5 ounces of zinc down to ¼ ounce of zinc to the pound [of copper]. At Hegermühl, 11 parts of copper are alloyed with 2 of zinc to make a red brass, which is afterward rolled into sheets. At Nürnberg, ''Dutch foil'' is made from a similar alloy.<ref name=Piggot/>{{rp|p. 355}}</blockquote>Piggot also states separately that the brass used for machinery and locomotives in England was composed of copper 74.5%, zinc 25%, and lead 0.5%,<ref name=Piggot>{{cite book| author = Piggot, Aaron Snowden | date = 1858 | title = The Chemistry and Metallurgy of Copper | edition = illustrated | location = Philadelphia, PA | publisher = Lindsay and Blakiston | page = 354f | isbn = 9780608406817 | url = https://books.google.com/books?newbks=0&id=XnIQAAAAIAAJ&q=tombak#v=snippet&q=tombak&f=false | access-date = 2026-05-13 | quote = [Subtitle] Including a Description of the Principal Copper Mines of the United States and Other Countries, the Art of Mining and Preparing Ores for Market, and the Various Processes of Copper Smelting, &c.}}</ref>{{rp|p. 354}} a combination that would make it a tombac according to Ure.{{cn|date=May 2026}}{{or|date=May 2026}}
Other tombac compositions that Ure reports are:<ref name=Ure1856/>{{rp|p. 243}} * "tombak for making gilt articles"— ** Copper 82.0%, zinc 18.0%, lead 1.5%, tin 3.%; ** Copper 82%, zinc 18%, lead 3%, tin 1%; and ** Copper 82.3%, zinc 17.5%, tin 0.2%.<ref name=Ure1856/>{{rp|p. 243}} And * "French tombak for sword handles, &c.": copper 80%, zinc 17%, tin 3%; * "tombak of the Okar, near Goslar, in the Hartz": copper 80%, zinc 17%, tin 3%; * "yellow tombak of Paris for gilt ornaments": copper 85%, zinc 15%, tin a trace percentage; * "tombak for [gilt ornaments] from... Hanover": copper 85.3%, zinc 14.7%; * a tombak he refers to as "chrysochalk": copper 86%, zinc 14%;<ref name=Ure1856/>{{rp|p. 243}}<ref>Erhard Brepohl purportedly lists the composition of chrysochalk, which he refers to as "Alkeizatlee", as being: copper 66.4%, zinc 16.6%, lead 5.7%, tin 10%, magnesium 1.3%, see {{Cite book | author = Brepohl, Erhard | orig-date = 1962 | date = 1982 | title = Теория и практика ювелирного дела | trans-title = Theorie und Proxis des Goldschmieds [Theory and Practice of the Goldsmiths; Russian translation, "...of Jewelry Making"] | location = Leipzig, Germany | publisher = Veb. Fachbuchverlag | url=https://djvu.online/file/JWrBoH0g0FwEz | access-date=2026-05-13 | page = | language=ru}}{{failed verification|date=May 2026}}{{page needed|date=May 2026}}{{dubious|date=May 2026}} Note, this citation is an amalgam of the original German edition, the source of the Russian translation, and the translated volume (both incomplete). The publisher's information is from the German source edition, the web link is to the Russian translation (the details of which have yet to be extracted).<!--Without knowing the page number intended for this citation, it is a near useless citation, esp. given the Russian; and one cannot determine what of the preceding content it was intended to cover.--><!--There is no mention of "Chrysochalk" or "Alkeizatlee" in the Ure (1839) source, neither at the page linked, or anywhere we could determine. Moved this reference, with editing, to another position in this section, where it is relevant.: {{Cite book |last=Ure |first=Andrew |url=http://archive.org/details/b2930345x |title=A dictionary of arts, manufactures, and mines: containing a clear exposition of their principles and practice |date=1839 |publisher=London : Longman, Orme, Brown, Greene, & Longmans |others=Wellcome Library}}--></ref> * "Red tombac from Paris": copper 90.0%, zinc 7.9%, 1.6% lead; and * "Red tombac of Vienna": copper 97.8%, zinc 2.2%.<ref name=Ure1856/>{{rp|p. 243}}
Other alloy formulations include:{{says who|date=May 2026}} * "white tombac": ca. 90% copper and 10% zinc, with trace arsenic;{{cn|date=May 2026}} and * "enamel" or "emailler tombak", suitable for enamelling{{says who|date=May 2026}}: ca: 95% copper and 5% zinc.{{cn|date=May 2026}}
Ure goes on to report a further composition, with proportions given in the "parts" of each metal— * "Prince's metal": 3 parts copper and 1 part zinc.<ref name=Ure1856/>{{rp|p. 243}}
He then goes on to report further compositions, in "parts", starting from copper and "yellow brass" (the "mean proportion... [of that being] 30 zinc to 70 copper"<ref name=Ure1856/>{{rp|p. 243}}), rather than presenting fundamental constituents— * "Pinchbeck": "2 parts copper and 1 yellow brass";<ref name=Ure1856/>{{rp|p. 243}}<ref>By observation, this Pinchbeck is 2 parts copper, and, from the yellow brass, 0.7 parts copper and 0.3 parts zinc, or, ''in toto'', 2.7 parts copper and 0.3 parts zinc (i.e., 9 parts copper and 1 part zinc).</ref> and * "Mannheim gold (semilor)": 2.8 parts copper, 1.2 parts yellow brass, 0.3 parts tin.<ref name=Ure1856/>{{rp|p. 243}}<ref>Each numeric component of this Ure formulation is presented here, divided by 10, to make its comparison to Pinchbeck the easier.</ref><ref>By observation, this Mannheim gold is 2.8 parts copper, and, from the yellow brass, (0.7 x 1.2) parts copper and (0.3 x 1.2) parts zinc; simplifying and including the tin, this is (2.80 + 0.84) parts copper, 0.36 parts zinc, 0.3 parts tin. Summing and simplifying, this is, ''in toto'', 3.64 parts copper, 0.36 parts zinc, and 0.3 parts tin (i.e., 10.11 parts copper, 1.00 parts zinc, and 0.83 parts tin).</ref> Ure goes on to note that the alloy from which a form of "white metal buttons" are cast is composed of 3.2 parts yellow brass, 0.4 parts zinc, 0.2 parts tin.<ref name=Ure1856/>{{rp|p. 243}}<ref>See the notes that follow, and the described composition of Prince's metal, above.</ref><ref>Each numeric component of this Ure formulation are again presented here, divided by 10, for consistency.</ref><ref>By observation, this cast button alloy is, from the yellow brass and zinc, (3.2 x 0.7) parts copper, and (3.2 x 0.3) plus 0.4 parts zinc, plus its 0.2 parts tin, or, simplifying, 2.24 parts copper, (0.36 + 0.4) parts zinc, 0.2 parts tin. Summing, this is, ''in toto'', 2.24 parts copper, 0.76 parts zinc, and 0.2 parts tin (i.e., 2.95 parts copper, 1.00 parts zinc, and 0.26 parts tin).</ref>
With regard to modern forms, compositions include:{{says who|date=May 2026}} * "CuZn15" (DIN, ISO):{{what|date=May 2026}} UNS, C23000; BS, CW 502L (CZ 102){{what|date=May 2026}}—tombac with gold colour, good for cold forming, suitable for pressing, hammering, or embossing;{{cn|date=May 2026}} * "CuZn12":{{what|date=May 2026}} a non-standardized tombac form, with same characteristics and applications as CuZn15, but of slightly different colour;{{cn|date=May 2026}} * "CuZn10" (DIN, ISO):{{what|date=May 2026}} UNS, C22000; BS, CW 501L (CZ 101){{what|date=May 2026}}–tombak with similar characteristics and applications as CuZn15 and CuZn12, but with a noticeable reddish colour.{{cn|date=May 2026}}
===Tempers=== Typical tempers are soft annealed and rolled hard.{{cn|date=May 2026}}
==Applications== [[Image:1980 Summer Olympics bronze medal.JPG|thumb|A "bronze" medal (actually tombac) from the 1980 Summer Olympics]]
{{refimprove section|date=May 2026}} <!--Each purported nonWP:SKYISBLUE fact should be sourced.-->
Tombac is soft and easy to work by hand: hand tools can easily punch, cut, enamel, repousse, engrave, gild, or etch it. It has a higher sheen than most brasses or copper, and does not easily tarnish. Historically, it was used by the Javanese as a {{lang |fr |faux}} gold finish for {{lang |fr |objects d'art}} and ornaments. * Most commonly, tombac in modern society is used in medals and awards of lesser importance, such as the German Oldenburg Long-Service Medallion for their Gendarmerie, and the Visit to Ireland Medal 1900 for the Irish police forces.<ref>{{cite book |last=Craig |first=John Herbert McCutcheon |title=The Mint; a history of the London Mint from A.D. 287 to 1948 |date=1953 |publisher=Cambridge University Press |page=325 |url=https://archive.org/details/minthistoryoflon0000crai/page/325/mode/1up}}</ref> *The {{lang |de |Pickelhaube}} and cuirass of the Imperial German and Prussian Army were at one time made of tombac. * German, particularly Prussian, field uniforms (which were also sold to equip the White Russians), had buttons and decorative fittings made of tombac. * Currently, tombac foils are used in arts and crafts for decorative articles, especially as an economic alternative to very expensive gold leaf. * Industry uses tombac foil for heating foils and etch applications. * Gilding metal is a type of tombac which is one of the most common jacketing materials for full metal and hollow-point jacketed bullets. * The 1980 Olympic 'Bronze' medals were actually tombac. * During World War II, the Royal Canadian Mint produced 5-cent pieces (nickels) in tombac in 1942 and 1943. * The German military used it for some combat medals during World War II. * The Swedish Armed Forces adopted a special-service round for the Carl Gustav m/45 submachine gun with a tombac-plated steel jacket surrounding the lead core of the bullet loaded in the cartridge. While the lands of the barrel can cut into the tombac, the steel jacket resists deformation and thus causes the gas pressure to rise higher than the previous soft-jacketed m/39, giving the {{convert |6.8 |g |gr |adj=on}} bullet a muzzle velocity of {{convert|420|m/s|ft/s|abbr=on|0}}.<ref>Arméstabens taktiska avdelning februari 1962 : "Erfarenheterna från striderna i Kongo under september och december 1961"</ref> * Brass alloys, including tombak, are occasionally used in architecture, such as ornaments, roofs or outside wall plating. It withstands corrosion well.<ref>{{cite web|url=https://www.rotaxmetals.net/brass-sheet-metal-dealer-on-the-alloys-use-in-architectural-projects/|title=Brass Sheet Metal Dealer on the Alloy's Use in Architectural Projects|publisher=Rotax Metals|date=31 July 2014|accessdate=14 July 2019}}</ref>
==See also== *{{annotated link|Tumbaga}}
==References== {{reflist}}
==External links== {{wiktionary}} *[https://web.archive.org/web/20080302034606/http://www.npi.gov.au/database/substance-info/profiles/27.html National Pollutant Inventory - Copper and compounds fact sheet] *[http://www.diracdelta.co.uk/science/source/t/o/tombac/source.html Tombac - DiracDelta Science & Engineering Encyclopedia] *[http://www.kaisersbunker.com/pt/pickelhaube.htm The Line Pickelhaube] (Detailed explanation of Pickelhaube and use of Tombak for economic reasons) * Schlenk German tombak manufacturer: [http://www.schlenk.de]
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Category:Copper alloys Category:Zinc alloys Category:Coinage metals and alloys