Introduced December 1953 at $152.50, the 10.5cm f2.5 was one of NK's more historically important lenses. Approximately 9000 were produced starting with SN812000 and a second batch of approximately 13,000 onsetted with SN912000. All 22000 were substantially identical in a black and chrome motif (black painted body, chrome grip/mounting ring and chrome filter ring) with three significant variations.

Variations 1: Early SN812XXX up the forward portion of the chrome lens barrel has studs for a bayonet mount lens shade. (colon at the end of the serial number sub variation)
Variation 1(NikonBM)
Variation 1(LeicaSM)
Variation 1(ContaxBM)

Variations 2: In the same serial number block continuing after the studded barrel lenses change to a more conventional clip on hood and the hood studs vanish.
Variation 2(NikonBM)
Variation 2(LeicaSM)
Variation 2(ContaxBM)

Variations 3: Onset serial number 912501 to 926158
Variation 3(NikonBM)
Variation 3(LeicaSM)
Variation 3(ContaxBM)

This lens was such a remarkably excellent formulation that it not only was one of the very best of that era, guaranteeing Nikon's impressively growing reputation in that very competitive emerging world market, that it survived the demise of Nikon's rangefinder line in 1962 and persisted in Nikon's reflex camera arsenal for decades until being replaced by the Micro 105mm f2.8 after about three more decades.

The actual lens formulation is largely a scaled up variation of the 8.5cm f2.0 (shown below for comparison) with its edges cut off to yield an f2.5 formulation. It works extraordinarily well. While the original 8.5 f2.0 is a very fine lens, the 10.5cm f2.5 has turned out to be an historically most extraordinary one.