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The Onoto No 8 Mammoth Plunger Filler

This edition is now SOLD OUT
In high density black acrylic with genuine
woolly mammoth tusk more than 10,000 years old!

And featuring the famous Onoto vacuum filling mechanism! 

The Onoto Mammoth Plunger-filler

The pen that’s been more than 10,000 years in the making!

When Onoto first introduced The Mammoth to its range in 1924, it soon became a firm favourite with writers. Its obvious size made it a ‘statement pen’ with gentlemen of the time and of course the giant No. 8 gold Onoto nib was renowned for its smoothness. The plunger-filling system first introduced by De La Rue in 1905 was scaled up for the Mammoth to give it huge ink capacity too.

It’s long been our intention to reintroduce the Mammoth and now, 90 years later, here it is: The new Onoto Mammoth Plunger-filler with, of course, a giant No. 8 18ct gold nib!

But that’s not all…

Apart from the nib, this new Mammoth has another unique feature: The plunger knob is made from genuine woolly mammoth tusk that’s more than 10,000 years old!

A firm favourite

The plunger–filling system was introduced by Onoto in 1905 and became a hugely popular characteristic of the brand. It was eventually withdrawn in the 1950s partly because of the cost of manufacturing such an intricate mechanism and partly because of the fashion for more streamlined pens. However, it remained a firm favourite with Onoto enthusiasts and collectors around the world, and following many requests, we have recreated a true plunger-filling mechanism.

Virtually maintenance-free

The Onoto Mammoth Plunger-filler has an impeccable lineage and has been developed using original Onoto drawings: the same classic design; the same chevron clip; the same plunger-filler vacuum system. However, key components are now made from better materials than those which existed 50 years ago. For example, the plunger rod is made of carbon fibre; the cup valves are a special silicone rubber and there's an ingenious 3 washer seal that we believe gives a much longer life than the original cork seals. This makes the brand new Onoto Mammoth virtually maintenance free.

Huge ink capacity

What’s more, the ink capacity is 3 mls, more than 4 times the capacity of a standard K5 converter or cartridge, so you have much longer writing time than most modern fountain pens.

Cut off valve prevents leaking

And, just like the original plunger-filler, The Mammoth Plunger-filler also features a cut-off valve which seals the ink reservoir when the pen isn't in use. Simply turn the ivory cap by half a turn and it's ready to write!

Limited availability

The Onoto No. 8 Mammoth Plunger–filler is issued in a worldwide limited edition of just 25 pens.

Onoto giant No.8 nib – super–smooth in 18ct gold

Put ‘pen to paper’ and you’ll be amazed at the smoothness of the exclusive Onoto 18ct gold #8 nib, available in broad or medium widths to suit your handwriting style.

Custom nibs also available

And if you prefer to use a special nib – a fine, italic, stub or oblique, for example – you can have our No. 8 18ct gold nib ground to your exact specification by one of the UK’s leading nib-masters. Just complete your requirements in the shopping cart.

And for that extra touch ...

Whether for yourself or as a gift, you can have the Mammoth Plunger-filler engraved on the barrel with a name or initials for that touch of exclusivity at a modest extra cost.

Video demonstration showing how to fill an Onoto Mammoth Plunger-Filler

Please click on the videos below to play.  Once playing, you can use the controls at the bottom right of the video windows to change the video quality or to play video at full screen size.

The origin of woolly mammoth ivory
Where does it come from – and isn’t it illegal to sell ivory? These are the two most frequently asked questions we have received as we created the Mammoth pen. We have been very careful in determining the provenance of the woolly mammoth ivory and confirm that it has been acquired through regular commercial trade sources. It originates from Siberia where there have been many excavations of woolly mammoth in recent years. Mammoth tusk is not a restricted article under CITES (Convention on International Trade in Endangered Species of Wildlife Fauna and Flora) so there is open trade in mammoth ivory.

Mammoth illustration

The ivory components in the Mammoth pen have been manufactured in the UK from extinct mammoth tusk that’s at least 10,000 years old and which has been fully authenticated by Schreger line measurements of <90deg and UV light characteristics.

The Onoto Mammoth Plunger-filler

Certificate of Authenticity/Origin

Each Onoto Mammoth Plunger-filler comes in a superb burr wood presentation box with a signed and numbered Certificate of Authenticity and Origin confirming its limited edition status and the provenance of the mammoth ivory. The limited edition number is also engraved on the barrel.

Made in England – just like vintage Onotos

The Onoto Mammoth Plunger-filler is completely hand-made in England and bears the words:

Made in England

engraved on the barrel just like its 1920s predecessor, when famous patrons like Winston Churchill, Ernest Shackleton, Natsume Soseki and Field Marshall Haig relied on their Onoto pens to communicate great words of wisdom. Click here for more information on the history of Onoto pens.

Read what our customers say about Onoto

Thousands of modern Onoto pens have been sold around the world, and many customers write to us expressing their delight with their new Onoto. Click here to read what our customers think of their new Onoto pen.

The Onoto Mammoth Plunger-filler

No Risk, 30 Day 100% Refund GUARANTEE
You can acquire the Onoto Mammoth Plunger-filler without risk, thanks to our 30 day 100% refund guarantee. It is a cornerstone of our business that if for any reason, you wish to return the pen, you may do so within 30 days of receipt for a full refund of the purchase price, without question.

 Worldwide delivery

The Onoto Mammoth Plunger-filler may be delivered anywhere in the world, fully insured, for just £10.

Specification Table
Limited Edition:
25 worldwide
Material: Cap and barrel: High density acrylic
Plunger knob: Woolly mammoth ivory over 10,000 years old
Fittings: 23ct gold-plated silver
Nib: Onoto size 8 in 18ct gold with rhodium plate
Nib Options: Medium or broad nib as standard.
Ink feed:
Plunger-filler only
Capped (closed): 162 mm
Uncapped including nib:  136 mm
Posted including nib:
180 mm
Cap length: 67 mm
Barrel diameter: 13mm tapering to 11mm
Cap diameter 16 mm
Weight: 27 gms

Limited edition: 25 worldwide

The Onoto No 8 Mammoth Plunger Filler


Select Your Preferred Nib Style (required field)
Custom Nib
Custom Nib £36
Personal Engraving

Pricing and Quantity

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the UK/EU, please click here and select the appropriate cart
so that you are not charged European sales tax (VAT).

Price: £1,194.00 (excluding your options)


Special Instructions

Alternatively, please email or telephone +44 (0) 1603 811165 and we will send you an order form.

Business Terms and Conditions

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