In 1949, the New Aero-metric Parker 51 was launched in the USA and described as a clear case of improving on perfection.
All Aerometric pens were single-jeweled. 
custom, Gold filled with alternating 4 vertical lines and plain band, this is the most common GF design View cart for details. 
Although it has often been repeated as fact that 51s bearing a "T"-prefix date code were assembled in Parker's Toronto plant, there are strong reasons to doubt this (full discussion here). Makes any Parker 51 suitable for a desk set. In Absolute MINT Condition. Another Parker "51" was also added to the series in 1950, the Parker "51" Special. In Absolute MINT Unused condition in original Box. There are some things that give it away, though: the dimensions didn't change too much, but the new 51 did get ever so slightly longer. Plum (aka Aubergine) The MKII type 2 pens were not produced in this colour What I did find particularly noticeable, and even a bit bothersome is that both nibs seem to have a particularly fussy and narrow sweet spot in how you rotate the nib. Aerometric fill. In 1957 Introduced the Parker "51" Insignia but this was really only a renamed Signet. First-year examples, such as the pen above, had a number of distinctive features, including "jewels" at both the cap top and barrel end (more on first-years); from then through 1948, pens could be single- or double-jeweled -- though double-jewel pens postdating 1946 are very much the exception. Parker also made 51s in South America at its factory in Argentina. To criticise the adoption of a cartridge/convertor filling system is a nonsense. Both in Perfect condition but with some plate loss on clip points. Scarce USA Parker 51 Custom in Cocoa with Gold filled cap. Despite the cap finial of the modern P51 really just being a single part, the stepped shape and 'jewel' insert somewhat recreates the look of the vintage. Nassau Green (aka Sage) The sectional view below comes from a Parker repair manual from 1947. Fitted with the original 14kt gold super smooth medium to fine tipped nib. 
Works perfectly. Early USA Parker 51 Vacumatic in Black with Sterling Silver Cap. Mechanically, it seems to be closer to the 51 copycats of the 1940s, such as the Waterman Taperite and the Eversharp Fifth Avenue, or to the later Parker 45.
First, starting in 1943, the year of making was printed at the bottom of the tubular nib, but of course dating from the nib is inexact at best, as the nib is one of the most frequently replaced parts. After numerous reports of cracked barrels, Parker manufactured a quantity of thicker-walled replacement barrels. In the late 1950's the gold cap ring was deleted from the Flighter pen. Aerometric fill. Aerometric Demis are slightly longer than Vac-filler Demis, and more slender. Fitted with the original 14kt gold, super smooth fine tipped nib. While you can find a slight hard start from time to time, it never really dries out over longer periods of time, and usually starts right up again. Surprisingly, the roles are reversed when uncapped: here, the modern P51 is 4 mm shorter, coming in at just 12,3 cm (4.84"). There's been some confusion, since David Shepherd chose in this book "Parker 51" not to count the Vacumatic filler as MK I, instead starting with the first aerometric model. This flexes a rubber diaphragm attached to the plunger with the partial vacuum drawing ink into the barrel. The filling system was instead moved to the Parker 45, introduced in 1960. HERITAGE COLLECTABLES FULLY RESTORED VINTAGE WRITING INSTRUMENTS. Not worth the trouble to me! Heritage GF cap solid 14k gold clip, "squares" Parker 51 in Teal Green With Stainless Cap. With sales in excess of 20 million pens, it was like a pen from another planet! It rapidly became 'the world's most wanted pen', It was first launched to the American public in January 1941 in just four colours: India Black, Cedar Blue, Dover Grey and Cordovan Brown with a wide choice of cap styles. But precisely. The most obvious variations were that the barrel imprints were at the filler end rather than next to the clutch ring, and both jewels were metal rather than plastic, Above: In 1947-48 Parker produced a demi-sized version of the 51 Vacumatic. Vacumatic; cross-section above) to a squeeze-bulb ("Aerometric") with a transparent "Pli-Glass" sac (see photo below). Powered by, L to R: Vintage P51 gold-filled, modern P51 Deluxe, Vintage P51 'Lustraloy', modern P51. A Signet/Insignia and a Flighter Parker "51". Same goes for the 18k nib option for about $250. Market prices are significantly lower already and the Deluxe might be one of the cheapest gold nibbed pens you can get right now.Nice review and I agree, the new 51s are much better than their reputation. Also in 1948 The Parker "51" Signet was introduced with an all GF cap and barrel with vertical lines. The Demi pens were not made in this style. Scarce USA Parker 51 in Forest Green with Stainless Cap. Parker 51 Custom in Teal Green with gold filled cap. No risk of accidental uncapping and an inky mess. The new 51 looks quite nice but I still think the original pen has cleaner lines. The barrel colours were: The small digit denotes the year of making for the barrel. On both my vintage pens, the cap feels mushy and it's hard to tell if it clicked on properly or not. Sterling Silver plain with GF clip and chevron band In Near MINT Condition. RARE USA Parker 51 Aerometric Demonstrator Fountain Pen Clear Body and Cap model with gold filled trim. Both in Mint condition in original box. I also like the Parker 75 but I keep going back to one of my Parker 51 pens. Parker 51 Custom in Burgundy with Gold filled cap. While the earlier filler had the larger ink capacity, the Aerometric was simpler and more robust, with a more intuitive mode of filling and a special vented sterling silver breather tube to reduce the likelihood of leakage during flight. PARKER 51 COCOA DEMI AEROMETRIC Fountain Pen + Pencil [1951] [FULLY RESTORED], VINTAGE PARKER 51 AEROMETRIC Fountain Pen [c1950s] [FULLY RESTORED]. Lustraloy with Chrome Plated clip All rights reserved. It never leaked, always worked and rarely broke. Secondly an imprint can be found on the top of the barrel, just under the cap clutch ring: I had an IM with a giant slit under the clip, and a Sonnet with those finial air holes, and both of them dried out if I left them more than 2 days without writing. A short model, known as the Demi, was introduced shortly before the Vacumatic filler was phased out. It might become grounds for confusion, but In this article the Vacumatic filler will be referred to as the MK I, the Aerometric with the rounded end as the MK II, the aerometric with the plastic jeweled "61" style cap and squarish end as the MK III and the aerometric with the metal jeweled "61" style cap as the MK IV. Importantly, the front shell and barrel were still made from lucite with the barrel threading being the same as on the Mk1, This is only intended to be a very brief overview of the key immediate visual features of the various 51 models to help with a quick initial identification. Fitted with the original 14kt gold, super smooth medium to fine tipped nib. An uncapped Demi is about 11.2cms long whereas the full sized 51 is 12.8cms, In 1947, Parkers factory in England also started producing 51s for the British and European markets and, with the Vacumatic filling system being seen as overly complicated, Parker worked towards a new type of filler which was longer lasting, more reliable and simpler to use. Unless otherwise noted, the caps are of Lustraloy, Parker's matte-finished stainless steel. Midnight Blue (aka Dark Blue) here are also examples of Demonstrators, a pen in all aspects like the ordinary Parker "51" but made in clear plastic, showing the workings inside the pen, primarely made for pen sellers. Smooth Finish with Chevron Cap Band. They dry the nib out making the whole thing unusable over time. The MK II can also be divided into MK II-A, with the longer clip cap, (identical to the MK I-B), the MK II-B with a shorter clip and MK II-C with an even shorter clip with fewer feathers and the "halo" logo on the cap. Fitted with the original 14kt gold, super smooth medium to fine tipped nib. Fitted with the original 14kt gold, super smooth medium tipped nib. Note the fine-finned "collector" under the hood and surrounding the base of the nib. Two Vacumatic filled Parker "51" in Dove Grey The U.S. design patent for the Parker 51 was 116,097. Instead of the button operated rubber diaphragm filler, this new 51 came with a PVC pli-glass reservoir with a 30 year life expectancy - an astonishingly long life given that most pens then required a service every 5 years or so. Fitted with the original 14kt gold, super smooth medium to fine tipped nib. Basic Parker 51 Aerometric Repair In Original Box. Where the steel nib is reliable but a bit bland, the gold nib on the Deluxe is much more interesting to write with and even has a slightly stubby tipping shape that offers some line variation. Called almost a blasphemy by some, I actually think it's an improvement over the original. Fountain Pen and Ballpoint. PARKER "51" 6 MADE IN U.S.A. Current Parker ballpoint refills fit the 51 Jotters, but the Liquid Lead refills (which reportedly never worked all that well) have long been unavailable. Cedar Blue When uncapped, the modern Parker 51 (Left) is a bit shorter than its vintage counterpart! Insignia, Gold filled with alternating 9 vertical lines plain band Parker date codes -- The clip is often referred to as the "transitional clip and the pens could be categorised as the MK I-B. n 1954 the engraving Made In USA was added to the back of the cap. Fitted with the original 14kt gold super smooth Medium to broad tipped nib. Fitted with the original 14kt gold super smooth Medium tipped nib.
Burgundy In 2002 Parker launched a retro model, the Parker "51" Special Edition in one of its rarest finishes, the Empire State Building etched cap. Also in 1950 the Parker "51" Flighter was introduced. Parker hasn't been doing aerometric-style (or for that matter, Vacumatic pump-filler) mechanisms for years at this point. Although the "Pli-Glass" material has often been misidentified as nylon, these sacs were in fact made of PVC (vinyl). Mark I (1942-48), had the (late) Vacumatic filling system with a plastic plunger hidden behind a blind cap. Parker 51 Clutch Pencil in Black with Stainless cap. Note the distict features, Double aluminium jewels, metal filler with diamond imprint. Canadian Parker 51 Vacumatic in Black with Stainless cap and gold filled trim. Far too much. Aerometric 51s used a transparent synthetic sac that is extremely durable but prone to darkening (new replacements are available here. The c/c filling system was obviously to be expected. There's really no excuse for not including a converter with a 90 pen, and then charging a ridiculous 8 to 10 extra euros for one. The gold-nibbed Deluxe version is a slightly different beast though. The new filling system was initially advertised as the "Foto-Fill" filler, with the term "Aero-metric" applied to the pressure-equalizing venting system provided by the specially-designed sterling silver breather tube. Parker 51 in Black with Stainless cap. Aerometric fill. the Empire State in solid two-tone gold. For more on the origins of the 51, see the article by Zazove & Fultz in the Fall 2000 issue of The PENnant, now available online here. Why oh why would any pen designer put airholes under the finial, except to use a little less metal? Named after Parkers 51st anniversary, the Parker 51 has without doubt been one of the most successful pens ever made. "MADE IN U.S.A. 50". Cap screw now in metal, section ring wider again. So it is sometimes tricky to see the orientation of the nib properly. And that effect seems to be magnified by the fact that the hooded nib sort of obstructs your view. To complicate things further there's also a MK I-B, a transitional Vacumatic filler with the new style non-blue diamond cap with a long clip. Scarce Parker 51 Custom Mark 2 SET in Teal Green with Gold fill caps. Forest green This had the aerometric filling system but in the manner of the Demi "51" with a U-shaped pressure bar. In late 1947 Parker in Newhaven, UK, started to produce Vacumatic filler Parker "51"'s, although no double jewelled pens were offered and the pens only came in the colours of India Black, Cedar Blue, Dove Grey and Cordovan Brown. Sure, the vintage P51 is a fantastic pen for its age, but one has to be able to admit that it isn't without its flaws either! Especially from afar, you'd be forgiven for not being able to distinguish between the old and new. Of course the original Parker 51 -as with many vintage pens- isn't a terribly large pen. The MKII pens of course had a brand new filling system that was to be adopted by virtually all Parkers in the future, the Aerometric. In MINT Condition. This transparent demonstrator reveals the fine-finned "collector" hidden under the 51's hood. Blue Diamond clips are normally gold-filled, whereas the later arrow clips usually (but not always) match the cap's color. Colour ranges, cap styles and the timing of design changes vary between Parker's factories in the USA, UK and elsewhere: detailing these variations are way beyond the scope of this little summary. Among other things, this article provides annual sales figures for the 51: An important article by Fultz, Zazove, & Hiscock, "The Parker 51 Before 1941: Development and Test Marketing", is found in Pen World, 17/7 (Aug/Sept 2004). At least in the condition that original vintage P51's are in at this point -often well-used throughout the years- I'm not a particularly big fan of how the clutch-style cap works. There seems to be a problem serving the request at this time, {"modules":["unloadOptimization","bandwidthDetection"],"unloadOptimization":{"browsers":{"Firefox":true,"Chrome":true}},"bandwidthDetection":{"url":"https://ir.ebaystatic.com/cr/v/c1/thirtysevens.jpg","maxViews":4,"imgSize":37,"expiry":300000,"timeout":250}}. Design changes were relatively few. The brand is taking advantage of its customers. Dove grey Vintage and Modern Pen SpecialistsPO Box 295, Hexham NE46 9HS01434 683 162 (Mon-Fri 11am-4pm)orders@penhome.co.uk, The original Parker 51 pen was the biggest selling and probably most practical fountain pen ever made. This supply was soon exhausted, however, and before long it became clear that even the replacement barrels were crack-prone. Between the standard version with brushed steel cap, and the 'Deluxe' with gold-plated details, the designs perfectly mimic the two vintage P51 (both aerometrics) I own: one with guilloche gold-filled cap and one with the 'Lustraloy' brushed steel cap. This essay should help put to rest the persistent myth of Moholy-Nagy as the designer of the 51, restoring credit to the designing trio of Marlin Baker, Gaylen Sayler, and Milton Pickus. Demonstrators in clear Lucite were made for dealer use, but not sold to the general public. pencilcaseblog.com 2021 All Rights Reserved. But then again, our hobby is centered around personal tastes and very subtle preferences, so you'll always find pro's and cons For me,the best writing pen, ever, is the Parker 51 (ie the original one). As it stands now, only the Deluxe version gets one as standard. I think opinions in general have already become a bit more nuanced, showing that it certainly isn't all bad as some would suggest in the past. Heirloom, all solid 14k gold, plain All parts except for the barrel and cap were identical to the full sized 51. In Near MINT Condition. Most European pens had screw or pump plungers (Mont Blanc, Pelikan etc) while the American pen companies preferred rubber sacs with different levers or plungers. In 1956 the ink Superchrome engraving on the metal filler sleeve with filling instructions was replaced with Parker ink. Fitted with the original RARE 14kt gold Stub italic medium tipped nib giving a superb writing style. barrel, c. 1964. Parker 51 Custom in Black with gold filled filled cap. Often a "working" Vac-filler which still has its old diaphragm will begin to show irregular flow, or will even release a sudden flood of ink as the age-rotten rubber fails. The Mark I Parker "51" came in seven colours: India Black The contents of most of the articles noted above have been incorporated into the text of an outstanding monograph on the 51, written by David and Mark Shepherd and privately printed at the end of 2004. Cedar Blue Please donate to help me keep this site online. The metal 'jewel' finial is actually surprisingly historically correct, as the very first P51's came with an aluminum jewe!