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Parker 51 Fountain Pen

The Parker 51 was a fountain pen produced by the Parker Pen Company, of Janesville, Wisconsin, from 1941 through 1972. The Parker 51 was sold with aerometric and vacumatic filling systems and also had a hooded nib, which kept most of the nib hidden under the pen’s plastic body.

The Parker 51 is a very popular pen with fountain pen collectors and is one of the most famous fountain pens of all time.

Parker 51 Name Origin

It might seem confusing that the Parker 51 was released in 1941, but there is a perfectly sensible reason: the pen was developed in 1939, the Parker Pen Company’s 51st year after being founded. So the name marks the birthday of the pen company, not the year the pen was released.

The name is also confusing because the Parker 51 was sold with a vacumatic filling system, but there is completely separate pen known as the Parker Vacumatic. This pen was Parker’s flagship from 1933 through 1941, before which it was known as the Vacuum Filler.

Parker 51 Vacumatic

Parker 51 Prominent Features

The Parker 51 is an iconic pen due to its overall design, but it has a number of distinctive features associated with it.

Aerometric Filling System

Introduced in 1948, this is one of the two filling systems used by the Parker 51. This system used a push button (known as the “pressure bar”) on the side of the pen’s interior, which could only be seen with the barrel of the pen removed. By submerging the tip of the pen in ink, pressing the bar, and then letting go, ink would be sucked into the inside of the pen’s rubber sac.

The ink is held inside of a rubber sac and there is no actual spring inside, but rather a springy steel bar that goes across the sac, which would press it down and then return to its original position to suck ink inside. By pressing multiple times on the bar with the tip submerged the maximum ink capacity could be held.

The instructions were printed on the inside of the pen, directly into the body of the aerometric filler:

To Fill
Press Ribber Bar
Firmly Four Times
Holding Pen Point
Down, Wipe Point
With Soft Tissue

Vacumatic Filling System

This is the push-button filling system that looks like the more advanced of the two designs featured in the P51, but is actually the older design (the pen was introduced in 1941 with this system). This is the filling system featured in the Marlin S. Baker’s 1939 patent as well.

Parker51 Patent Crop - Vacumatic

The vacumatic system has a push button at the top of the interior of the pen. To fill the pen the user simply needs to submerge the tip of the pen in ink, press the button, and then let go of the button, allowing it to return to its original position. On the return it will fill the interior with ink. The vacumatic system also has a small rubber diaphragm, inside that takes in the ink.

At the release of the pen this system was known as the “Foto-fill Filler” system and was lauded for only having a single moving part.

Hooded Nib

The Parker 51 does not have a large, highly stylized nib like many classic fountain pens. This was a workhorse pen, used when fountain pens were daily tools. In 1941 this took form in a 14K gold tubular nib, most of which was concealed within the body of the pen. The nib works with a collector shell, breather tube, and feed to produce smooth, even writing.

The nib is called “hood” because the grip section of then pen hides most of it from view, similar to on the newer Lamy 2000. It’s called tubular because it’s literally shaped like a tube that wraps entirely around the feed. This is usually done to delay the drying of ink that is still inside the pen. This was specially useful with the 51 pens because it was released alongside new, quick-drying inks. These were the Parker SuperChrome inks, which are now know to be harmful to pens and paper alike due to their high acidity and corrosive nature.

Parker 51 Versions

A large number of P51 variants exist and telling them apart from one another isn’t always easy. That said, there are some major classes of 51s what are worth understanding.

  • First Year: These were the P51s sold in 1940-1941. They have a vacumatic fill and they are almost always a “double jewel” which is to say that they have a jewel piece on the cap and the bottom of the pen. The jewel is usually made of aluminum and would generally be called a finial today. These also have a larger than average diamond on the top of the clip, usually in blue. The fill button on these early pens will be aluminum, just like those found on the Parker Vacumatic.
  • Vacumatic: They have the older filling system based on the combination of a rubber sac and a push button that is hidden under a blind cap that unscrews from the to top of the pen.
  • Aerometric: The new filling mechanism. Also based around a rubber sac, but using a pressure bar and full removable barrel.
  • Gold-filled: A Parker 51 with a gold cap. The cap is not gold-plated, but “gold-filled” which means a thicker plating of gold is used. The cap is not solid gold.
  • Flighter: A full stainless steel P51

Parker 51 Fountain Pen Information

Street Price Check Price
Manufacturer Parker
Pen Type Fountain Pen | Vacuum (built-in), Piston (built-in)
Barrel Color Black, Brushed Steel, Blue, Green, Mustard, White, Red
Barrel Material Plastic
Grip Color Black
Grip Material Plastic
Country of Origin USA
MSRP $50
Still Sold Yes
Release Year1941
Similar To
Capped? Retractable?Capped - Snap On
Weight (g)
Nib Material
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