If the name on your safe is Mosler, it came from the Ohio firm, first in Cincinnati and then in Hamilton, that made everything from office safes to the vault that guarded the Declaration of Independence. Here’s the company’s real history, how to tell which kind of Mosler you’ve got and date it from the serial number, and what it’s worth, weighs and needs if nobody knows the combination.
1867
Founding year in Mosler’s own histories (Cincinnati)
1891
Production starts at Hamilton, Ohio
50 tons
National Archives vault for the Charters of Freedom, 1952
2001
Bankruptcy; Diebold buys the assets
Key takeaways
- Gustave Mosler, an Austrian immigrant, started Mosler, Bahmann & Co. in Cincinnati in the late 1860s (1867, 1869 or 1870, depending on the source). After his death in 1874 his sons ran their own rival firm, and the two Mosler companies fought in court in the 1880s.
- The family firm moved to Hamilton, Ohio, in 1891, so “Hamilton, O.” on a Mosler means 1891 or later and “Cincinnati” means earlier.
- Mosler published its own serial number list from 1886: “handle numbers” before 1946, lot numbers with a dash from 1946 to 1989, and numbers from 30,000 without a dash after that.
- Mosler kept no record of customers’ combinations, so a lost combination means a safe technician, not a phone call to Diebold.
- Old Mosler office and record safes are valued mainly as working safes; salesman’s samples and restored cannonball bank safes are the collectors’ pieces.
- The Hiroshima vaults were real, but the story reached the public through Mosler’s publicity, and the bank’s own letter says the doors were heavily damaged.
- Mosler went bankrupt in August 2001 and Diebold bought most of its business that October.
In This Article
Mosler at a glance
| Country | United States (Cincinnati, then Hamilton, Ohio) |
| Founded | 1867 as Mosler, Bahmann & Co. by Mosler’s account (the Smithsonian gives 1869, Cincinnati directories point to 1870; a c.1960 catalogue claims “since 1848”) |
| Founder | Gustave Mosler (1816–1874), with Frederick (Fred) Bahmann |
| Family firms | Mosler Safe & Lock Co. and Mosler Bank Safe Co. (Cincinnati, 1880s–1891); The Mosler Safe Co. (Hamilton, from 1891); Mosler Inc. (later years) |
| Works | Several sites in Cincinnati (Pearl, Elm, Fourth and Front streets); Grand Boulevard, Hamilton (1891–1996); a later plant at Orangeburg, South Carolina |
| Known for | Bank vaults and vault doors, screw-door bank safes, time locks, office and record safes, drive-up banking equipment, government security containers |
| Owners | Mosler family to 1967; American Standard 1967–1986; managers and investors 1986–2001 |
| End | Ceased trading 3 August 2001, Chapter 11 filed 6 August 2001; assets bought by Diebold on 25 October 2001 |
| Successor | Diebold, which bought the US and Canadian business in 2001 (Diebold Nixdorf since 2016) |
History of the Mosler Safe Company
Cincinnati beginnings and the Bahmann split
Gustave Mosler (1816–1874) came to the United States from Austria in 1849. According to the Smithsonian’s archivists he joined the Cincinnati safe makers Diebold, Bahmann & Co. in 1859, the firm from which Diebold grew, before setting up Mosler, Bahmann & Co. with Frederick (Fred) Bahmann. When that happened is less settled than you’d expect. The Smithsonian dates that partnership to 1869; Mosler’s own histories and Hamilton’s local historians give 1867. Canton historian Edward Heald, working from the Cincinnati city directories, found that Bahmann left Diebold to join Mosler in 1870.1,2,3,4
After Gustave’s death in 1874 his sons went their own way. Moses, William, Max and Julius Mosler ran what became the Mosler Safe & Lock Co., while Mosler, Bahmann & Co., with Bahmann as president around 1879–80, carried on as a separate corporation in the same city.1,5 By the early 1880s the two were rivals. In 1883 Moses Mosler patented a fire-proof safe body built on bent angle-iron frames with rounded corners and assigned the patents to the Mosler Safe & Lock Co., which then sued Mosler, Bahmann & Co. for making round-cornered safes. The case reached the US Supreme Court, which on 14 May 1888 found the angle-bar claims invalid: cutting and bending an angle iron, it said, was what “would occur to a mechanic of ordinary skill”.5,6 Mosler, Bahmann & Co. is generally said to have lasted until about 1898.7
Mosler later claimed that its safes had come through the Chicago fire of 1871 and the Boston fire of 1872 with their contents intact. Those testimonials survive in Mosler’s own publicity, and in 1871 the family business was still Mosler, Bahmann & Co., so treat them as advertising.8
Hamilton, Ohio, “safe capital”
By 1890 the family ran two firms, the Mosler Safe and Lock Co. at Front and Elm streets and the Mosler Bank Safe Co. on Front Street, both on Cincinnati’s flood-prone riverfront. The Hamilton Democrat reported that their shops were “utterly inadequate”, so Mosler went shopping for a new home. It weighed Canton, Piqua, Sidney, Toledo, Columbus and Aurora, Indiana, before signing a contract with Hamilton businessmen on 5 July 1890: ten acres and $85,000, raised by selling building lots on the land around the works.2
The move began on 21 September 1891 and production started on 12 October at Grand Boulevard and the Miami-Erie Canal, with Moses Mosler as president. Workers were expected to rise from 400 to 600.2 Mosler soon had company. Herring-Hall-Marvin broke ground across Grand Boulevard in 1896, with Moses Mosler among those who persuaded it to come, and in 1907 Mosler bought the old Macneale & Urban works on Hamilton’s west side.2 Read more in our history of Herring-Hall-Marvin safes.
In 1895 Mosler bought the Corliss Safe Co. of Providence, Rhode Island, maker of a round bank safe (see our guide to cannonball safes), and sold “Mosler-Corliss” products until about 1910; a December 1895 notice described the Mosler Safe Company as “operating the Mosler & Corliss Safe factories”.9 In 1892 the Mosler Safe & Lock Co. and Mosler, Bahmann & Co. were both named among the firms to be united in the Diebold-Mosler-Damon Company, a $5,000,000 New Jersey combination formed in answer to the Herring-Hall-Marvin merger, which made little mark.10,11 A 1936 Hamilton newspaper said that in “almost any store or bank” Americans saw the words “Mosler Safe Company, Hamilton, Ohio, USA”.8,12
Timeline
- 1867 Gustave Mosler and Frederick Bahmann found Mosler, Bahmann & Co. in Cincinnati.
- 1874 Gustave Mosler dies; his sons build up the rival Mosler Safe & Lock Co.
- 1887 Mosler enters the time lock business by buying Beard & Brothers.
- 1888 The Supreme Court rules against Moses Mosler’s round-corner safe patent.
- 1891 The family firm moves to Hamilton, Ohio.
- 1895 Mosler buys the Corliss Safe Co. of Providence.
- 1936 Vault doors shipped for the Bullion Depository at Fort Knox.
- 1952 The National Archives vault for the Charters of Freedom is built at Hamilton.
- 1967 The family sells Mosler to American Standard, which sells it to managers and investors in 1986.
- 2001 Bankruptcy in August; Diebold buys the assets in October.
Bank safes, vault doors and time locks
A Mosler trade card of the early 1900s (the picture at the top of this page) shows three products: the square “Mosler Patent” fire-proof safe, the round Mosler-Corliss patent bank safe and the Mosler patent screw-door bank safe, whose round door screwed into its body.13 Our history of safe-cracking explains why banks wanted them.
The company entered the time lock business in 1887 by buying Beard & Brothers and its patent rights. Its first model kept the Beard design almost unchanged, with two 48-hour E. Howard clock movements under one dial; collectors believe about 400 were made.14 By 1951 a standard Mosler 7-inch bank vault door had 20 steel bolts, a Mosler triple-movement 120-hour time lock, two Mosler combination locks “capable of 100,000,000 changes” and a relocking device.15 See our guide to safe lock mechanisms for how time locks work.
Big vault work became Mosler’s showcase. Its 1922 Mosler Messenger described a round vault door about 32 inches thick at the Mellon National Bank in Pittsburgh, manganese steel vaults at the Merchants National Bank of Los Angeles, and a vault door for the Federal Reserve Bank in Kansas City hauled from the rail yard by four five-ton lorries, a tractor and four draught horses.16 In the 1920s Mosler also held a patent on an “explosion chamber” around the safe door, and lost a 1927 Supreme Court case against a rival it accused of passing off a plain metal band as one.17
Fort Knox: what the record shows
The Fort Knox claim is old. On 19 December 1936, the month the Bullion Depository was completed, the Hamilton Journal-News named “the building of the vaults for the United States gold reserve at Fort Knox” as Mosler’s most prominent recent achievement.12 According to Mosler’s own account, the vault door was shipped from Hamilton in June 1936, weighed 20 tons and was 21 inches thick, built in seven laminations of tool- and torch-resisting steel.8
We haven’t found a Treasury or Mint document that names the maker, so the attribution rests on Mosler and the Hamilton press of 1936. Mosler’s figures match the “about 20 tons” usually quoted for the door. For what is publicly known about the depository itself, see the most secure bank vaults in the world.
The National Archives vault, 1952
In April 1952 Congress ordered the Declaration of Independence and the Constitution moved from the Library of Congress to the National Archives. Mosler built the storage vault at Hamilton in 1952, with engineers working round the clock, and installed it in Washington. It was a 50-ton safe of steel and reinforced concrete about 20 feet below the exhibition hall floor. Every night an elevator lowered the documents into it, display cases and all.18
The documents went in on 13 December 1952, and President Truman dedicated the shrine on 15 December, Bill of Rights Day.19,18 Former employees recall that Mosler did the work without charge.20 In 1954 company president Edwin Mosler Jr. presented a 600-pound working model of the vault to Vice President Nixon. The real vault was removed during the renovation of the National Archives Building in the early 2000s; when Mosler closed in 2001 it gave its own model to the Butler County Historical Society in Hamilton.19
“As safe from destruction as anything that the wit of modern man could devise.”
President Harry Truman, 15 December 1952
Did a Mosler vault survive Hiroshima?
Yes, but the story needs care. The building was the Hiroshima branch of the Teikoku Bank, a two-storey reinforced concrete bank built in 1925 for the Mitsui Bank, about 360 m from the hypocentre. It was badly damaged, and none of the night staff or the twelve or thirteen women working inside are known to have survived.21 Don’t be thrown by the two bank names: Mitsui merged with Dai-Ichi to form Teikoku in 1943, and the Mitsui name returned in 1954.22
The earliest accounts all passed through Mosler. A US Army lieutenant wrote to the company in early 1946 that four Mosler vaults in the building were intact. Bill Geerhart, who traced the story, thinks Mosler’s copywriters polished the letter. The Hamilton Journal-Daily News carried the story on 10 July 1946, and American Banker followed on 13 July with “Will U.S. Vaults Resist Atom Bombs? Hiroshima Experience Proves They Do”, using photos supplied by Mosler. A report commissioned by Mosler said its vaults at the Teikoku Bank in Hiroshima and the Geibi Bank in Kure were working.23
The most useful evidence is a letter of 22 May 1950 from the branch manager after the bank reopened. He wrote that the surface of the vault doors was heavily damaged but that “the cash and important documents were perfectly saved”, and that the bank’s customers admired Mosler’s products as “stronger than the atomic bomb”. Mosler used that line in its publicity for at least a decade, and individual banks advertised their own Mosler vaults with the company’s Hiroshima photographs.23,8 The bank building was repaired and later became the Hiroshima Andersen bakery.21 More wartime stories are in safes and vaults of World War II.
Atomic tests and Cold War doors
Mosler went on to test its products against atomic blasts. In 1955 its engineers placed 25 document and money safes at different distances from a nuclear test at Yucca Flat, Nevada; Edwin Mosler Jr. admitted that “the closest ones went around the world in a cloud of dust”.8 In the 1957 Plumbbob series a Mosler vault 11 feet high, 10 feet wide and 17 feet long was set where the blast would reach about 75 psi. The concrete slabs on its sides were ripped off and the door trim loosened, but the steel door still worked.24
Government work followed. Around 1960 Mosler built the two vehicle blast doors for the secret congressional fallout shelter under the Greenbrier resort in West Virginia; the one photographed at the works is 19.5 inches thick and over 20 tons.25 Former employees remember jobs at the White House, the Pentagon, Atomic Energy Commission sites, Strategic Air Command bases, and the depositories at Fort Knox and West Point.20 Mosler also made security containers for classified government papers.3
Drive-up banking, takeovers and the 2001 collapse
Edwin H. Mosler Sr. was president from 1922 to 1952; his son Edwin Jr. led the company in the 1950s and 1960s and retired as chairman in 1966.8,20 Banking moved to the car, and Mosler moved with it. A long-serving installer recalled that Mosler fitted the first drive-in window at the First National Bank of Boston in 1939, followed by the periscope-like Snorkel, pneumatic tube systems and an early cash machine, the Tellermatic. By the 1960s the national service division brought in about a third of Mosler’s revenue.20
The family sold Mosler to American Standard in 1967. In 1986 American Standard sold it to a group of Mosler managers and outside investors.7,12 The Grand Boulevard plant closed in 1996; the head office on Berk Boulevard, Hamilton, lasted until the end.20 Mosler Inc. stopped operating on 3 August 2001 and filed for Chapter 11 in Delaware on 6 August, citing a long-standing debt burden, a failed computer system and trouble absorbing acquisitions. About 1,800 people lost their jobs.26 On 25 October 2001 Diebold bought Mosler’s security business, service operations and related property in the United States and Canada for about $33.4 million including fees.27
Which Mosler safe do you have?
Mosler made far more than bank vaults. The safes that turn up in homes, offices, shops and old bank buildings fall into a handful of types, and each has its own dating clues. Mosler’s own rule of thumb is worth knowing first: a money safe or money chest resists burglary but not fire, while a record safe or insulated file resists fire but not burglary.28
| Type | What it looks like | Dating clues |
|---|---|---|
| Decorated fire-proof safe (“Mosler Patent”) | Square iron safe, often on castors, with painted panels, lines and gold lettering13,3 | Cincinnati name or address: before 1891. “Hamilton, O.”: 1891 or later. Mosler said safes made before 1918, or without a UL listing, should not be treated as fire-proof.28 |
| Screw-door and cannonball bank safe | Round door that screws into a round or drum body, sometimes on a base, with the bank’s name painted on the door | “Mosler-Corliss”: about 1895–1910. A documented Mosler example from the Farmers State Bank, Milan, Indiana, is dated 1917.9,29 |
| Salesman’s sample | A working miniature, about 17 inches long or high, in a carrying case | Carried by salesmen to show the full-size safe, so it dates with the cannonball and screw-door types.30,31 |
| Record safe (insulated) | Single or double door, with a fire label inside or on the door | Model number from inside height and width plus label class, for example 3360-A, 4820-B or 1612-C. A Mosler double-door “A” label record safe was rated for four hours at 2000°F.28,32 Date it from the serial number. |
| Money chest and deposit safe | Small, very thick steel body; night deposit safes have a chute from the street | The 1952 day and night deposit safes Nos. 12 and 14 had a 1-inch steel body, a door up to 3 inches thick and a four-tumbler combination lock.33 |
| Insulated file | Two, three or four-drawer filing cabinet in letter or legal size | Styled by Henry Dreyfuss around 1960. Files numbered 15527-1 to 22627-106, made up to 1972, contain a thin asbestos sheet.34,28 |
| Bank vault door | Round or rectangular door with many bolts and time locks on the inside, sometimes with a day gate | Around 1960 standard doors ran up to 16 inches thick and the “Century” series came in 3½, 7, 10, 12 and 16-inch models; the 1951 7-inch door had 20 bolts.34,15 |
| Fire-resistive vault or file room door | Flat-sill door in an office or records room, 78 × 32 inch opening (42 inches for a double door), with an escape handle inside | Models FS-6, FS-4, FS-2, FS-1 and 32 carried UL labels for 6, 4, 2, 1 and ½ hour; around 1960 they came in mist green, tan or grey.34 |
| Government security container | Grey steel filing cabinet with a combination dial on each drawer or door | Mosler made security containers for classified papers and the GSA MRK-302 combination lock. The Defense Department found no asbestos in the Mosler containers it tested.3,35,36 |
| Safe deposit box and key | Bank box doors and numbered keys marked Mosler | The number tells a technician how the key is cut, not which bank it belongs to.28 |
Fire-resisting files and safes made before 2000 may contain asbestos, so never cut, drill or grind one; our guide to asbestos in old safes explains what to check.
How to identify and date a Mosler safe
Recognising a Mosler is rarely the hard part, because the company put its name and town on almost everything. Dating one takes four clues: the name, the town, the serial number and the labels.
Clue 1
Name and town
“Mosler, Bahmann & Co.”: the Bahmann firm, Cincinnati, about 1867–1898. “Mosler Safe & Lock Co.” or “Mosler Bank Safe Co., Cincinnati”: before 1891. “The Mosler Safe Co., Hamilton, O.”: 1891 or later. “Mosler-Corliss”: about 1895–1910.5,2,8
Clue 2
Serial number
Before 1946 the number was a “handle number”, usually stamped on the handle. From 1946 to 1989 it was a lot number plus a dash number (for example 12214-4). Safes from the later Orangeburg plant start at 30,000 with no dash. The lookup table is below.37
Other things to look for
- Locks. Mosler made its own time locks and combination locks and fitted them to its vault doors. A Mosler time lock dates the door, not necessarily the safe.15,14
- Finish. Mosler’s own history says its early safes were decorated with gold leaf and hand-painted scenes. Around 1960 Mosler offered vault doors in mist green, tan and grey, and its insulated files were styled by Henry Dreyfuss.3,34
- Two numbers. A fire label from Underwriters Laboratories or the SMNA carries its own number. For dating, use Mosler’s number: the handle number, or the lot and dash number on the serial plate.28
Mosler safe serial number lookup
Here Mosler did owners a real favour. In 1999 it put its own list of “safe serial numbers cross referenced to manufacturing dates” on its website, giving the first number issued each year from 1886 to 1992.37 First work out which numbering system your safe uses, then find the last year whose starting number is at or below yours. Our free How old is my safe? tool does the lookup for you, and our safe serial number lookup covers other makers.
Step 1: which kind of number is it?
| Your number looks like | What it is | Years |
|---|---|---|
| A number with a dash, for example 12214-4 | Lot number, then the unit’s place in that lot | 1946–1989 |
| 30,000 or more, no dash | Orangeburg, South Carolina, numbering | From about 1990 |
| Six digits, no dash (100046 and up) | Handle number | 1891–1945 |
| Five digits from 50717 to 99999, no dash | Handle number | 1886–1891 |
| Below 50717, no dash | Before 1886, or not a Mosler serial number (check for a label number) | Not covered by the list |
Step 2: find the year
The table gives every fifth year. Lot 12345, for example, falls between 1955 (11848) and 1960 (14338); the full list below narrows it to 1956, which is also the example Mosler used.37
| Year | First serial number that year |
|---|---|
| 1886 | 50717 |
| 1890 | 95530 |
| 1895 | 121102 |
| 1900 | 146889 |
| 1905 | 183574 |
| 1910 | 222927 |
| 1915 | 258394 |
| 1920 | 287743 |
| 1925 | 303898 |
| 1930 | 323417 |
| 1935 | 342731 |
| 1940 | 364880 |
| 1945 | 438547 |
| 1946 (lot-dash system begins) | 9024 |
| 1950 | 10131 |
| 1955 | 11848 |
| 1960 | 14338 |
| 1965 | 17291 |
| 1970 | 21090 |
| 1975 | 24041 |
| 1980 | 25989 |
| 1985 | 27669 |
| 1990 | 29380 |
| 1992 | 32400 |
Full year-by-year list, 1886–1945 (handle numbers)
1886: 50717 · 1887: 78657 · 1888: 84617 · 1889: 90196 · 1890: 95530 · 1891: 100046 · 1892: 106257 · 1893: 110461 · 1894: 115767 · 1895: 121102 · 1896: 125947 · 1897: 130880 · 1898: 135318 · 1899: 140451 · 1900: 146889 · 1901: 153849 · 1902: 161418 · 1903: 168668 · 1904: 176237 · 1905: 183574 · 1906: 190882 · 1907: 199264 · 1908: 205674 · 1909: 213388 · 1910: 222927 · 1911: 231134 · 1912: 239225 · 1913: 247403 · 1914: 253174 · 1915: 258394 · 1916: 265585 · 1917: 271009 · 1918: 273388 · 1919: 278839 · 1920: 287743 · 1921: 290469 · 1922: not listed · 1923: 301415 · 1924: 302663 · 1925: 303898 · 1926: 305989 · 1927: 309379 · 1928: 314038 · 1929: 318541 · 1930: 323417 · 1931: 327160 · 1932: 331904 · 1933: 334952 · 1934: 338601 · 1935: 342731 · 1936: 346504 · 1937: 351836 · 1938: 355991 · 1939: 359691 · 1940: 364880 · 1941: 372831 · 1942: 391329 · 1943: 421321 · 1944: 428744 · 1945: 438547
Full year-by-year list, 1946–1992 (lot numbers)
1946: 9024 · 1947: 9266 · 1948: 9507 · 1949: 9851 · 1950: 10131 · 1951: 10570 · 1952: 10881 · 1953: 11253 · 1954: 11544 · 1955: 11848 · 1956: 12214 · 1957: 12623 · 1958: 13144 · 1959: 13676 · 1960: 14338 · 1961: 14878 · 1962: 15455 · 1963: 16044 · 1964: 16688 · 1965: 17291 · 1966: 18139 · 1967: 19020 · 1968: 19650 · 1969: 20375 · 1970: 21090 · 1971: 21787 · 1972: 22472 · 1973: 23156 · 1974: 23661 · 1975: 24041 · 1976: 24327 · 1977: 24701 · 1978: 25118 · 1979: 25486 · 1980: 25989 · 1981: 26434 · 1982: 26740 · 1983: 26959 · 1984: 27284 · 1985: 27669 · 1986: 28133 · 1987: 28513 · 1988: 28835 · 1989: 29100 · 1990: 29380 · 1991: 31315 · 1992: 32400
Treat the result as a guide. The list starts in 1886, so earlier Mosler safes can’t be dated this way, and it skips 1922. The numbers before 1891 have only five digits even though Mosler’s own FAQ said pre-1946 numbers had six, and safe technicians have questioned some entries.37,28 For other dating methods, see how to date an old safe.
Mosler myths and facts
Mosler built the first fire-resistant safe.
Mosler’s 1998 website said so, but fire-resisting safes were sold decades before 1867. See who invented the fireproof safe.
Mosler has been making safes since 1848.
A c.1960 catalogue says so, but Gustave Mosler only reached America in 1849. The firm dates from 1867 (or 1869).
The Hiroshima vault came through untouched.
The bank wrote that the doors were heavily damaged. The contents survived.
Willie Sutton said “Mosler, you build one hell of a safe.”
That is Mosler’s 1998 wording. His 1953 memoir is quoted as “Those Mosler people certainly make safe safes.”
Sources for these points: Mosler’s 1998 history and c.1960 catalogue, the Smithsonian, the 1950 Teikoku letter and Jim Blount’s account of Sutton’s memoir.3,34,1,23,8
What is an old Mosler safe worth?
Even Mosler wouldn’t value its old safes: its advice was to ask several antique dealers.28 Auction records show where the money is, and size works against you. The Mosler pieces that make high prices are small, rare or restored, above all salesman’s samples and cannonball bank safes. Full-size bank safes, record safes and vault doors are heavy and costly to move, which keeps their prices down; most are valued mainly as working safes.
| Mosler safe | Sale | Price |
|---|---|---|
| Cannonball salesman’s sample in its case, about 17 in high | Morphy, October 2026 | $56,58031 |
| Cannonball salesman’s sample, “Manganese Steel Bank Safe”, original paint and case | Morphy, October 2016 | $15,60030 |
| “Square cannonball” salesman’s sample, about 1903, about 50 lb | Morphy, March 2013 | $11,21038 |
| Bank safe called “The Cannonball”, 1917, Farmers State Bank, Milan, Indiana, 3,300 lb | Cowan’s, November 2012 | $3,24029 |
| Two cannonball bank safes, older restorations, one with a top safe that would not open | Morphy, October 2025 | $2,040 and $2,40039 |
Prices include the buyer’s premium. These are the top of the market, not a guide to an ordinary office or record safe, and anything we say about value is an informal estimate, not a professional appraisal. Our guide to what old safes are worth covers condition, decoration, keys and selling costs, with more dated sales.
How much does a Mosler safe weigh?
Mosler answered this question with a chart. Its 1999 website told owners to find the model number first (inside height and width in inches plus the label class: a double-door safe 60 inches high and 33 wide inside with an “A” label is a 3360-A) and then look the weight up in its “Weights and Dimensions” chart.28 The chart was a downloadable PDF that the web archives didn’t keep, and we haven’t found a printed copy.40 So work out the model number anyway, measure the outside, and use our safe weight calculator or our guide to how much an old safe weighs. These are the Mosler weights we could document:
| Mosler item | Weight |
|---|---|
| “Square cannonball” salesman’s sample, about 1903 | About 50 lb (23 kg)38 |
| Working model of the National Archives vault, 1954 | 600 lb (272 kg)19 |
| Cannonball bank safe, 1917, Milan, Indiana | 3,300 lb (1,497 kg)29 |
| Fort Knox vault door, 1936 (Mosler’s figure) | 20 tons8 |
| Greenbrier bunker vehicle door, about 1960 | Over 20 tons25 |
| National Archives vault, 1952 | 50 tons18 |
Moving a Mosler safe
A 2024 survey of US locksmiths put a typical safe move at $250 to $500, depending on size and complexity; general removal firms often refuse anything heavy, and one Houston mover takes nothing over 600 lb (272 kg).41,42 Full-size Mosler bank safes weigh several times that (the 1917 Milan safe was 3,300 lb), so use a specialist safe mover and give them the model number, outside measurements and photos of the route. A vault door is part of the building and its removal is a job for a safe and vault technician. Our guide to moving or getting rid of an old safe covers quotes, scrap and selling.
Lost the combination to a Mosler safe?
No one can look it up. Mosler shipped new safes with a standard factory combination and instructions for changing it, and said plainly that it did “not have records for the combination to any previously purchased safes”.28 So no list passed to Diebold either. Mosler’s advice for a lost combination or key was to call a qualified safe technician, who can open the safe and fit a new combination or a key lock.28 In the US, the Safe & Vault Technicians Association lists qualified technicians.43
If you do have a combination, remember that Mosler fitted several different locks over the years.44 A four-number combination means a four-wheel lock (Mosler’s 1952 deposit safes used a four-tumbler lock), and it’s dialled differently from a three-number one.33 Mosler’s own instructions say spinning the dial “is unnecessary and may damage the lock” and, if the lock doesn’t work properly, “do not use force”.35 Forcing or drilling a door with a relocking device, which Mosler fitted to its vault and file room doors, can lock it for good.15,34 Our guide to old safe combination locks explains how they work and how to dial them, and locked out of an old safe covers what a technician does and charges.
“Mosler does not have records for the combination to any previously purchased safes.”
Mosler Inc., 1999
Who makes Mosler safes now?
Mosler Inc. stopped trading in August 2001. In October that year Diebold bought its security business, service operations and related property in the United States and Canada.26,27 Diebold became Diebold Nixdorf in 2016.45 For an owner, that means three things: there’s no Mosler factory to call, nobody holds a register of combinations or of who bought which safe, and the replacement parts Mosler offered in 1999 for safes made after 1970 came from a company that no longer exists.28 Repairs, parts and combination changes now go through independent safe technicians.
Not sure what you have? Send us photos of the lettering, labels and serial number and we’ll help you date your Mosler.
Frequently asked questions
Where is the serial number on a Mosler safe?
On older safes it’s the “handle number”, usually stamped on the door handle. Later safes carry it on a plate or label, often with the model number, so look on the door edge, the sides and inside. Don’t confuse it with the number on a UL or SMNA fire label.
How do I look up a Mosler safe serial number?
Use the free table above, taken from Mosler’s own 1999 list. A number with a dash means 1946 to 1989; six digits with no dash means 1891 to 1945; 30,000 or more without a dash means about 1990 or later. Then check the town: Cincinnati before 1891, Hamilton after.
What is an old Mosler safe worth?
Most are valued mainly as working safes. Salesman’s samples and restored cannonball bank safes are the exceptions: a Mosler cannonball sample made $56,580 at Morphy in October 2026, while two full-size cannonball safes sold for about $2,000 to $2,400 in October 2025. This is an informal guide, not an appraisal.
How much does a Mosler safe weigh?
It depends on the model, from about 50 lb for a salesman’s sample to 3,300 lb for a 1917 bank safe and many tons for a vault door. Work out the model number (inside height and width plus the label class) and use our safe weight calculator.
Can Diebold give me the combination to my Mosler safe?
No. Mosler said it kept no records of combinations for safes it had sold, so there was nothing to pass on. A qualified safe technician can open the safe and set a new combination.
Who owns Mosler now?
Mosler Inc. went bankrupt in 2001 and Diebold bought its security business and service operations in the US and Canada in October that year. Diebold is now Diebold Nixdorf.
Did Mosler build the Fort Knox vault?
Mosler and the Hamilton press said so in 1936, and its door figures match the published ones, but we haven’t found a government record naming the maker.
Are Mosler, Bahmann safes made by Mosler?
Yes and no. Gustave Mosler co-founded Mosler, Bahmann & Co., but after 1874 it was a separate company from his sons’ Mosler Safe & Lock Co., and the two were rivals.
Sources:
- Alison Oswald, “Safekeeping”, Lemelson Center, Smithsonian National Museum of American History, 27 June 2013. ↩︎
- Jim Blount, “Opening of Mosler Safe Co. continued festive mood in 1891 as Hamilton celebrated its centennial year”, Lane Libraries, Hamilton, 2014, compiled from the Hamilton Democrat of 1890–91 (archived copy). ↩︎
- Mosler Inc., “Mosler’s History”, mosler.com, ©1998 (archived 2 December 1998). Company marketing text. ↩︎
- Edward Thornton Heald, The Stark County Story, vol. 4: The American Way of Life (Canton: Stark County Historical Society, 1959), section “Company Foundations at Cincinnati, 1859–1871”, via Internet Archive (lending library; quoted from the full-text search). ↩︎
- The Mosler Safe and Lock Company v. Mosler, Bahman and Company, Transcript of Record, Supreme Court of the United States, October Term 1887, No. 248 (appeal from the Circuit Court, Southern District of Ohio), via Internet Archive. ↩︎
- Mosler Safe & Lock Co. v. Mosler, Bahmann & Co., 127 U.S. 354 (decided 14 May 1888), full text via Public.Resource.Org. ↩︎
- Wikipedia, “Mosler Safe Company”, citing the New York Times (13 February 1968) and Richard N. Piland, Hamilton’s Industrial Heritage (Arcadia, 2015). Used only for the 1967 sale and the end date of Mosler, Bahmann & Co. ↩︎
- Jim Blount, “Mosler Safe Co. reputation established by reports from 1871 Chicago fire, Fort Knox, White House, atomic bomb explosion, museums and frustrated safecrackers”, Lane Libraries, 2014, quoting a 1973 Mosler company history and Mosler publications (archived copy). ↩︎
- Commercial and Financial Chronicle, 7 December 1895, notice of the Mosler Safe Company “operating the Mosler & Corliss Safe factories”, via Internet Archive. ↩︎
- Engineering and Mining Journal, 19 November 1892, note on the Diebold-Mosler-Damon Safe Company, via Internet Archive. ↩︎
- Commercial and Financial Chronicle, 11 February 1893, “Diebold-Mosler-Damon Company”, via Internet Archive. ↩︎
- “Many of Largest Vaults by Mosler”, Hamilton Journal-News, 19 December 1936, transcribed by the Butler County Historical Society, “Mosler Safe” (archived copy), which also gives the 1986 sale and 1991 workforce. ↩︎
- Trade card of The Mosler Safe Co., Hamilton, Ohio (M. Mosler, president; W. Mosler, vice-president), early 20th century, via Wikimedia Commons (public domain). ↩︎
- Mosler time lock entries on my-time-machines.net, a time lock collection, citing David and Jean Erroll, American Genius: Nineteenth Century Bank Locks and Time Locks, p. 260. ↩︎
- The Mosler Safe Company, Bank Vault Door by Mosler (catalogue sheet, 1951), Building Technology Heritage Library via Internet Archive. ↩︎
- The Mosler Safe Company, Mosler Messenger, Vol. I No. 4, September 1922, Hamilton, Ohio, Building Technology Heritage Library via Internet Archive. ↩︎
- Mosler Safe Co. v. Ely-Norris Safe Co., 273 U.S. 132 (decided 17 January 1927), opinion via Internet Archive. ↩︎
- Jessie Kratz, “Protecting the Bill of Rights: the Mosler Vault”, Pieces of History, US National Archives, 17 December 2015. ↩︎
- Jessie Kratz, “The Mosler Model”, Pieces of History, US National Archives, 29 June 2020. ↩︎
- Jim Blount, “Mosler Safe Co., linked with banking for much of its history, also prominent contributor to U.S. Cold War defenses”, Lane Libraries, 2014, with recollections of former Mosler employees (archived copy). ↩︎
- Hiroshima Peace Memorial Museum, “Teikoku Bank Hiroshima Branch”, Virtual Museum. ↩︎
- Sumitomo Mitsui Banking Corporation, “History” (1943: Mitsui Bank and Dai-Ichi Bank merge to form Teikoku Bank; 1954: name restored to Mitsui Bank). ↩︎
- Bill Geerhart, “Unbreakable: Hiroshima and the Mosler Safe Company”, CONELRAD Adjacent, 26 August 2010, citing the Hamilton Journal-Daily News (10 July 1946), American Banker (13 July 1946) and Mosler’s company magazine Mpulse (1973). ↩︎
- National Nuclear Security Administration, Nevada Site Office, photograph PLU-57-182 and caption, Operation Plumbbob, 1957, via Wikimedia Commons. ↩︎
- Brookings Institution, U.S. Nuclear Weapons Cost Study Project (Atomic Audit, 1998), “Greenbrier bunker blast door”, photograph credited to the Mosler Safe Company. ↩︎
- ATM Marketplace, “Mosler files for Chapter 11”, 2001. ↩︎
- Diebold, Incorporated, Form 10-K405 for the year ended 31 December 2001, filed with the US Securities and Exchange Commission, 2002. ↩︎
- Mosler Inc., “Frequently asked questions about Mosler products”, mosler.com, ©1999 (archived 1 March 2000). ↩︎
- Cowan’s Auctions, Fall Fine & Decorative Art, 17 November 2012, lot 211, Mosler bank safe called “The Cannonball”, 1917, from the Farmers State Bank, Milan, Indiana, 3,300 lb (archived page), $3,240 including buyer’s premium. ↩︎
- Morphy Auctions, 29 October 2016, lot 165, salesman sample cannonball Mosler bank safe, “Manganese Steel Bank Safe”, 17 in long, original paint and case, $15,600 including buyer’s premium. ↩︎
- Morphy Auctions, Las Vegas, 16–17 October 2026, lot 1331, salesman sample “Cannonball” Mosler Safe Co. in box, about 17 inches high, estimate $15,000–25,000, final price $56,580 including buyer’s premium. ↩︎
- The Mosler Safe Company, “Tapeguard” and “Safe Range” mailing (undated advertising leaflet), Ted Nelson collection via Internet Archive. ↩︎
- The Mosler Safe Company, Mosler Day and Night Deposit Safe Nos. 12 and 14-SS (trade leaflet, 1952), Building Technology Heritage Library via Internet Archive. ↩︎
- The Mosler Safe Company, Mosler Safes and Vaults (trade catalogue, c.1960), Building Technology Heritage Library via Internet Archive. ↩︎
- The Mosler Safe Company, operating and changing instructions for the GSA MRK-302 combination lock (undated scan, archived from the University of Central Florida FISWG document library). ↩︎
- DoD Lock Program (US Navy), Security Facts!!, vol. 5, no. 1 (Summer 2002), “GSA-approved security containers do not contain asbestos”. ↩︎
- Mosler Inc., “Safe serial numbers cross referenced to manufacturing dates”, mosler.com, ©1999 (archived 10 October 2000). ↩︎
- Morphy Auctions, Premier Advertising sale, Denver, Pennsylvania, bidding closed 29 March 2013, prices including buyer’s premium: lot 189, Victor salesman sample screw-door cannonball, c.1905, about 68 lb, restored, $22,420; lot 149, Mosler salesman sample “square cannonball”, c.1903, about 50 lb, $11,210; lot 168, Marvin chrome iron spherical safe, about 2,000 lb, restored, $10,620; lot 166, the same type, about 650 lb, $10,030; lot 202, York Safe and Lock Co. manganese spherical safe, c.1899, about 450 lb, $9,440. Dates “circa” are the auction house’s. ↩︎
- Morphy Auctions, 16–18 October 2025, “The Moser [sic] Safe Co. cannonball safe”: lot 2438, labelled for the Osceola Bank, older restoration, top safe not opening, $2,040; lot 2439, $2,400 (prices including buyer’s premium). ↩︎
- Mosler Inc., “Weights and dimensions of safes”, mosler.com, ©1999 (archived 24 May 2000). The page offered a downloadable PDF chart; the PDF itself was not archived. ↩︎
- CLK Supplies, “Locksmith Price Survey Breakdown: What You Should Know for 2024” (21 October 2024), summarising the Locksmith Ledger 2024 National Locksmith Price Survey. ↩︎
- 3 Men Movers, Houston, Texas, “Safe movers” (checked 26 October 2026). A general removal firm’s published safe policy. ↩︎
- Safe & Vault Technicians Association, savta.org, “Safe Tech Search” (“Find a qualified technician”). ↩︎
- Lock Picking 101 forum, “This Old Safe” board, “3 digit combination fail” (June 2024): an owner’s Mosler safe and replies from the site administrator. ↩︎
- Wikipedia, “Diebold Nixdorf”, and the company filings it cites. ↩︎
