Short answer
A fake A. Lange & Söhne almost never copies the movement. Lange builds its own calibers in Glashütte, Saxony, and finishes them by hand. Replicas use third-party automatic movements with laser decoration. Four checks settle most cases: the movement number, the hand-engraved balance cock, the gold chatons, and the certificate. Price is the last filter. A used Lange 1 in gold trades near $25,000 to $40,000 US. A replica sells for $200 to $600.
1. Movement number and case number
Each Lange carries a movement number on the three-quarter plate and a case number on the case back. Both numbers appear in the guarantee certificate. Lange keeps an archive entry for each watch. A boutique or the Glashütte service center can confirm a number against that archive. On fakes the engraving depth is flat, the font is wrong, or the same number shows up on several watches from one seller.
2. The balance cock is hand-engraved
Lange cuts the balance cock engraving by hand. Each engraver works in a personal style, so the pattern differs from watch to watch. The lines are cut into the metal. Under 10x magnification the cuts show a V cross-section and changing depth. A replica shows a laser-etched pattern with even depth and a flat bottom. Fake engraving repeats the same motif at even spacing.
3. Three-quarter plate and gold chatons
Lange uses a three-quarter plate of untreated German silver. The metal reads pale yellow-white and darkens with age. Gold chatons hold the jewels, secured by blued screws. Bluing is a heat process, so the screw slot edge holds a dark ring and the surface shifts tone. Fakes use plated or painted screws. Fake chatons are brass rings with a gold wash.
4. The outsize date on the Lange 1
The Lange 1 date uses two discs, one for tens and one for units. On dates 1 through 9 the tens disc shows blank, so a gap sits at the seam. That gap is correct. On a real watch both digits sit on one plane and align inside a polished frame. On fakes the digits sit at different heights, tilt, or sit off-center in the aperture.
5. Case, dial, and crystal
Lange series cases come in 18k gold or platinum. Hallmarks sit inside the case back. Dial printing on gold dials holds a sharp edge at 10x. Fakes show ink spread on the logo and on the country of origin text. The crystal is sapphire with anti-reflective coating on both faces. Many fakes coat one face only and show a blue or purple cast.
6. Papers, box, and supply
Lange ships a printed certificate with the reference, the case metal, and the watch number. Lange makes about 5,000 to 6,000 watches a year, so the pool of used pieces is small. A seller who blocks a verification call or a service quote carries risk. A Lange at $2,000 does not exist.
Checklist
- Compare the movement number and case number to the certificate.
- Call a Lange boutique or service center to check the numbers.
- Inspect the balance cock engraving at 10x for cut lines.
- Check the chatons and screws for gold and heat bluing.
- Study the date aperture on a Lange 1 for plane alignment.
- Ask for a service history and the original box and papers.
- Compare the asking price to market data.