What do the twins mean?

They are the Zwilling mark, registered in 1871, and they date the mark rather than the razor. A Henckels razor carrying the twins is no earlier than 1871, which is a bound and not a year.

The maker's archive

Henckels razors.

J.A. Henckels is one of the oldest Solingen houses, in business from about 1731, and its marks are among the few with registration years. The registration gives a lower bound for any razor carrying the mark, and the sequence of marks is what separates the broad eras.

Country: Germany
Active since
Coverage: 1731–1950 · 3 code systems
Dating tier: Codes only
In the archive: 0 series · 3 code systems · 1 models
Years documented: 1731–1950

Eras

1871–1901

The twins appear

Zwilling, the twins, is registered in 1871; the forms J.A. Henckels and Henckels follow in 1898, Zwillinge in 1899 and Henckelswerke in 1901.

1908–1936

Twin Works and later

Twin Works is registered in 1908, and the interwar marks run through Acutal, Coltelleria, Noxida and Vacuum in 1924 and 1925, Genielos in 1929 and Sigma in 1936.

What dates this maker

The mark on the tang — its registration year is a lower bound: no earlier than the registration.
The sequence of marks: Zwilling 1871, Henckels 1898, Zwillinge 1899, Henckelswerke 1901, Twin Works 1908, the 1924 and 1925 group, Genielos 1929, Sigma 1936.
The firm floor of about 1731, which bounds how early any Henckels razor can be.
The country mark GERMANY, a lower bound of 1 March 1891.

Watch out

A mark registration is not a manufacture date: a Twin Works razor is no earlier than 1908, and could be much later.
The same mark can run for decades, so the sequence of marks separates eras and does not date individual razors.

J.A. Henckels (Zwilling / Twin Works) — marks and registration yearsa firm from c. 1731 to the present day; the marks were registered from 1871 → 1936 · 10 rows · Medium confidence

Country mark (lower bound, NOT a year)the requirement applies from 1 March 1891 (Tariff Act of 1890, also known as the McKinley Tariff) · 2 rows · High confidence

Grind, spine, scales, etching — era markers of a straight razor1700s → mid-1900s · 16 rows · Low confidence

1 Henckels models are catalogued with their production years, specs and safety notes.