CK 2998

Overview

The CK 2998 is the second-generation Speedmaster, launched in 1959 as successor to the CK 2915 Broad Arrow. It introduced two signatures that would define the line for decades: a black aluminium bezel with a tachymeter scale, and slender alpha (“leaf”) hour and minute hands. Every CK 2998 runs the hand-wound, column-wheel calibre 321. Eight sub-references are documented, each stamped inside the caseback after the hyphen: -1, -2, -3, -4, -5, -6, -61, -62 — each hyphen number marking a running change to bezels, hands, or dials. The -62 was the last iteration before the short-lived 105.002, which is nearly identical to a late 2998-62.

Case

About 39.7 mm across the bezel (which overhangs slightly), straight symmetrical lugs with 19 mm width — the classic pre-twisted-lug architecture. No crown guards; simple pump pushers; the correct crown is the flat-foot profile. The screw-down caseback carries the hippocampus (seahorse) medallion and “SPEEDMASTER,” cut in a distinctive double-bevel profile. The sub-reference is stamped on the inside of the caseback — the definitive sub-variant identifier.

Dial variants

All 2998 dials share a grammar, so sub-variants are identified by small details: applied metal Omega logo with printed “OMEGA” beneath and “Speedmaster” below — no 2998 carries the word “Professional.” Black matte, three registers, baton markers, outer minute track, “SWISS MADE” at 6. Early dials show the oval “O” carried over from the 2915; a circular “O” arrives from the 2998-3 onward.

The radium/tritium transition

The most consequential dial question on a 2998. Early dials used radium; Geiger-counter testing found the last sub-reference still registering radium was the 2998-4, with tritium generally accepted from roughly 1962. But dials left the factory unmarked — plain “Swiss Made” with no T's — until April 1, 1964, when T-marking became mandatory. So a late -61 or -62 with a tritium dial and plain “Swiss Made” is correct and expected; never demand “T SWISS MADE T” on a 1962 watch. The transition window is genuinely uncertain — a Geiger counter is the only honest test.

Per sub-variant

-1 dials most closely resemble the late 2915-3; the -4 differs specifically in its subsidiary-dial hands; -61 and -62 are the tritium-era dials described above. No verified source gives a single crisp dial detail separating -61 from -62 — treat them as a late-production continuum.

Bezel

The black aluminium tachymeter bezel is the 2998's other defining feature. The working map: 2998-1 and -2 carry the “Base 1000” bezel; from the 2998-3 through the -62, the standard “Base 500” tachymeter. All 2998 bezels use DON grammar — dot over 90, accent over the E in TACHYMETRE, dot at the lower right of the 70 — a key authenticity marker. Well-preserved bezels are uncommon; many originals have faded to the collector-nicknamed “grey ghost” — honest wear, often valued rather than penalized.

Hands, crystal

Hour/minute: alpha (leaf-shaped) on every 2998 — the single most reliable visual differentiator from the 2915's broad arrows and the later 105.003's batons. Chrono seconds: the detail collectors pay premiums for — slim straight hand on the earliest -1, the famous “lollipop” (luminous dot at the tip) on early-to-mid production, straight hand from the -3, and a white “drop tail” on late -61/-62 examples. Factory-original mixes were common, so absolute statements are hazardous. Crystal: domed hesalite with the etched Omega logo — routinely replaced; an unetched or sapphire crystal is an immediate red flag.

Bracelet

The most consistently documented factory fitment on late 2998s is the 7912 with No. 6 endlinks (clasp stampings dated to the early 1960s appear repeatedly on -61s). The flat-link 1039 with 516 endlinks is period-correct for straight-lug Speedmasters of the era but more strongly associated with the 105.002/105.003 — plausible on a 2998, not proven. Because bracelets were routinely swapped, a correct 7912/6 adds value but its absence is not fatal — the watch head matters more.

What to check before buying

• Caseback first. The inner back must be stamped with the full sub-reference. A ghost-faint seahorse suggests heavy polishing; lug bevels should still be visible — the “sleeve polish” that rounds these cases is the most common value-killer.
• Dial authenticity. Applied metal logo (never printed on originals), correct oval-vs-circular O, honest lume patina — creamy to copper on radium, lighter ivory on later tritium. Redial tells: glossy finish, wrong logo geometry, modern white lume, sloppy sub-register printing, or T-markings on a pre-April-1964 watch.
• Bezel. Confirm DON grammar. Reproduction DON bezels and later donor bezels are widespread; an unusually perfect bezel on a worn case deserves skepticism.
• Hands. Alpha hour/minute with lume matching the dial in tone — mismatched hand/dial lume color is the classic relume tell. Seconds-hand style should be plausible for the sub-variant.
• Crown, pushers, crystal. Flat-foot crown, pump pushers, etched hesalite — all frequently replaced in service.
• Movement. Calibre 321, 17 jewels, column wheel; serial in the accepted band for the sub-reference.
• Archive extracts. Omega generally cannot issue formal archive extracts for these early calibre-321 Speedmasters — don't walk away from a good -61/-62 over missing paperwork, and treat verbal museum confirmations as weaker than documents.