Fisher Space Pen Bullet 400TN Space Pen – Titanium Nitride, Gold

The Fisher Space Pen Series 400 was the brand's first model and remains its most sought-after product to this day. The pen is designed to work in conditions where ordinary pens simply fail.

The body is made of brass with a gold-colored titanium nitride coating. The tip of the refill is a tungsten carbide ball—a material known for its exceptional hardness and durability.

Why the Fisher Space Pen Is Different from Other Pens

The ink is thixotropic—it remains solid at rest but liquefies when writing. This means the pen doesn't leak or skip. It writes up to three times longer than standard ink.

Operates at temperatures ranging from -34°C to +120°C
It writes underwater and in zero gravity
It writes at any angle, including upside down
The magazine contains a pressurized nitrogen cartridge
Winter doesn't freeze, summer doesn't melt away

Compact and practical for any situation

When retracted, the pen is only 9.6 cm long, and when extended, it is 13.6 cm long. It fits easily into a wallet, organizer, or pocket. The metal clip secures it to the edge of a pocket or backpack.

It comes with an SPR4 refill—black ink, medium tip. Compatible with all Fisher PR refills. It comes in a plastic gift box.

The perfect gift for a man

Every Fisher Space Pen is hand-tested and comes with a lifetime warranty against manufacturing defects. It is ideal for doctors, lawyers, military personnel, police officers, business leaders, teachers, and anyone who values quality in their daily life.

The pen is practical, durable, and has an interesting story behind it—a great conversation starter and a memorable gift.

The History of the Space Pen

During the early NASA missions, astronauts used mechanical pencils. For the Gemini project in 1965, NASA purchased 34 mechanical pencils for a total of $4,382.50—about $128.89 each. The expense drew criticism, and the agency began looking for an alternative.

Paul S. Fisher of Fisher Pen Co. developed a new type of pressurized ink cartridge without funding from NASA. The company invested about $1 million of its own funds. The new pen worked in zero gravity, underwater, and at extreme temperatures.

In 1967, after rigorous testing, NASA equipped the Apollo astronauts with these pens. The media reported that about 400 pens were purchased at a price of $6 each. In February 1969, the Soviet Union also purchased 100 pens and 1,000 refills for the Soyuz missions. To this day, American astronauts and Russian cosmonauts use the Fisher Space Pen.

Specifications	Value
Brand	Fisher Space Pen
Model	400TN Solar Flame Titanium Nitride Bullet Pen
Type	Space Pen
Length when unfolded	13.6 cm
Length when folded	9.6 cm
Housing Material	Brass
Coverage	Titanium Nitride
Color	Titanium Nitride, gold-colored
Nozzle	Tungsten carbide
Magazine	SPR4 – black ink, medium thickness
Compatibility	All Fisher PR Fillers
Operating temperature	-34°C to +120°C
Warranty	Life-long
Contents of the Set	Pen and plastic gift box

Frequently Asked Questions

What makes the Fisher Space Pen 400TN different from a regular pen?

The Fisher Space Pen 400TN uses a pressurized ink cartridge powered by a nitrogen cartridge. The ink is thixotropic—it is solid at rest but liquefies when writing. The pen writes at any angle, including upside down, underwater, and in zero gravity. It operates at temperatures ranging from -34°C to +120°C. It doesn’t leak, doesn’t skip, and lasts up to three times longer than standard ink.

What materials is the Fisher Space Pen 400TN made of?

The pen body is made of brass with a gold-colored titanium nitride coating. The tip of the refill is made of tungsten carbide—a highly durable material. The design also includes steel components. The combination of these materials ensures durability and reliability for everyday use.

What are the dimensions of the Fisher Space Pen Bullet 400TN?

When retracted, the pen measures 9.6 cm, making it extremely compact. When extended, it reaches 13.6 cm—a comfortable length for writing. Its small size makes it easy to store in a wallet, organizer, or pocket. The metal clip secures it to the edge of a pocket or a backpack strap.

What type of cartridge does the 400TN model use, and can it be replaced?

The pen comes with an SPR4 refill—black ink with a medium line width. The refill is replaceable and compatible with all Fisher PR refills. This allows users to choose from a variety of ink colors and line widths according to their preferences.

Is the Fisher Space Pen 400TN a good gift for a man?

Yes, the Fisher Space Pen 400TN is an excellent gift for men in various professions and with diverse interests. It’s suitable for doctors, lawyers, military personnel, police officers, engineers, business leaders, and anyone who values functionality. The pen comes in a plastic gift box, ready to give. It comes with a lifetime warranty and has an interesting history tied to NASA’s space missions. At Dulotec.COM, you’ll find this model at a great price.

What is the history of the Fisher Space Pen, and how is it connected to NASA?

Paul S. Fisher developed the space pen without funding from NASA; the company invested approximately 1 million U.S. dollars from its own funds. By 1967, the pen had passed rigorous testing, and NASA equipped the Apollo astronauts with it. Approximately 400 pens were purchased at a price of $6 each. In 1969, the Soviet Union also purchased 100 pens for the Soyuz missions. To this day, the Fisher Space Pen is used by astronauts and cosmonauts.

What kind of warranty comes with the Fisher Space Pen 400TN?

Every Fisher Space Pen is precision-assembled and hand-tested before being released to the market. The 400TN model comes with a lifetime warranty against all manufacturing defects. This is a testament to the quality and reliability for which the Fisher brand has been known for decades. The warranty covers defects in materials and workmanship.