uni-ball Jetstream RT: Hybrid Ink, Tip Sizes & Refills

The 1.0 mm Jetstream RT drawn to scale from uni-ball UK's length.

Product facts

Product: uni-ball Jetstream RT Retractable Ballpoint (0.5 / 0.7 / 1.0 mm; SXN-210)
Brand: uni-ball
Brand origin: Japan
Made in: Japan^*
Material: PC/PP plastic barrel, rubber grip
Released: 2006^*
Price range: $under $5 per pen (multi-packs divided by the count)

Notes on these facts

Made by Mitsubishi Pencil Co., Ltd.. Made in Japan: per US business-supplier spec sheets for items 62152 (0.7 mm black), 62153 (0.7 mm blue) and 73834 (1.0 mm red), all listing Japan; Unsharpen also lists Japan. uni's US store, uni-ball UK and Mitsubishi Pencil's Japanese site don't state it. Source. Price: example listing. Released: Mitsubishi Pencil's February 17, 2011 press release says the Jetstream Standard went on sale in Japan in July 2006; we found no separate US launch date for the RT.
Price bands are typical US retail, checked October 2026. Conversions to US dollars are approximate, at October 2026 rates (US$1 = ¥158 = ₩1,330 = NT$32.5 = CN¥6.7 = SEK 9.9 = DKK 6.7 = ₺49.6 = C$1.41 = A$1.43; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).

Key takeaways

Mitsubishi Pencil launched the Jetstream line in Japan in July 2006 and says the series sells more than 100 million pens a year worldwide.
Three US ball sizes: 0.5 mm, 0.7 mm Fine and 1.0 mm, which uni's US store calls Medium and some retailers call Bold.
Refills are the Jetstream SXR family: SXR-5, SXR-7 and SXR-10; in the US the 1.0 mm black 2-pack is item 35972.
uni-ball UK lists the 1.0 mm RT (SXN-210) at 141.4 mm long, 11.7 mm across and 13.8 g; Unsharpen lists 11 g.
uni's own US store says Wirecutter has named the Jetstream RT its top pick since 2013.

What is the uni-ball Jetstream RT?

The Jetstream RT is the retractable, refillable US model of uni-ball’s Jetstream ballpoint, made by Mitsubishi Pencil of Japan. “RT” is short for retractable. Mitsubishi Pencil launched the Jetstream line in Japan in July 2006, and its press releases say the series now sells more than 100 million pens a year worldwide.

Unsharpen says the RT is sold in Japan as the Jetstream Rubber Body, whose whole barrel is rubber grip material. Mitsubishi Pencil’s Japanese site lists that model (SXN-250-07) only in 0.7 mm, for ¥275 (about US$1.70), so the 0.5 and 1.0 mm RT are export sizes.

In the US, uni-ball sold through Newell Brands for years. The Drum reports that the distribution deal ended in 2019 and that the company now sells under its own name, styled “uni”.

uni’s own US store says New York Times Wirecutter has named the Jetstream RT its “Top Pick Since 2013”. A 2013 blog post by Eugene Wei records the original pick, but we couldn’t open Wirecutter’s current page to confirm it still stands.

What does “hybrid ink” mean?

It means a ballpoint ink thinned out to write more like a gel pen: Mitsubishi Pencil calls it low-viscosity oil-based ink. Ordinary ballpoint ink is a thick oil paste, so it drags and can leave faint lines. Jetstream ink is oil-based but runs thinner, which is why uni-ball’s US packaging calls it a hybrid of gel smoothness and ballpoint drying speed.

Mitsubishi Pencil’s Japanese copy says the ink has up to 50% lower writing friction than its conventional oil-based ballpoints, combines pigment with new colorants for about twice the black density, and dries fast; a spring tip and twin-ball mechanism stop ink leaking or flowing back. In the US, uni markets the same ink as its Super Ink, resistant to check washing, water, fading and document alteration.

uni-ball Jetstream RT specs

Spec	Value
Maker	Mitsubishi Pencil Co., Ltd. (Japan), brand uni-ball
Type	Retractable ballpoint, low-viscosity oil-based pigment ink
Ball sizes (US)	0.5 mm · 0.7 mm Fine · 1.0 mm Medium (some retailers: Bold)
Refills	SXR-5 · SXR-7 · SXR-10
US refill 2-packs (1.0 mm)	35972 black · 35973 blue
Length (1.0 mm, SXN-210)	141.4 mm (5.6 in), per uni-ball UK
Weight	13.8 g per uni-ball UK; 11 g per unsharpen
Barrel / grip diameter	11.7 mm per uni-ball UK; 11.8 mm / 11.3 mm per unsharpen
US item / UPC	173832 (1.0 mm black, single) · 162152 (0.7 mm black, single, JAN 4902778805282)
Japanese equivalent	Jetstream Rubber Body SXN-250-07, 0.7 mm only, ¥275 (about US$1.70)
Launched	Jetstream line: July 2006 in Japan
Made in	Japan (per US supplier spec sheets)

Length, the 11.7 mm diameter and the 13.8 g weight come from uni-ball UK’s page for the 1.0 mm RT; the other diameters and the lighter 11 g figure come from the pen database unsharpen. The weights disagree, so we give both.

To-scale drawing of the three Jetstream RT ball sizes at 200 times: 0.5 mm, 0.7 mm and 1.0 mm, with refills SXR-5, SXR-7 and SXR-10 — The 1.0 mm ball is twice the diameter of the 0.5 mm, so it puts down a much heavier line.

Which Jetstream RT tip size should you choose?

Pick 0.7 mm Fine for everyday writing, 0.5 mm for small handwriting and 1.0 mm for signatures and bold, dark lines.

0.5 mm: the finest RT; it appears in fewer US listings than the other two.
0.7 mm Fine: the size most US packs are sold in, and the one in the Wirecutter claim.
1.0 mm: called “Medium” by uni’s US store, Quill and refill packs, and “Bold” by Staples and Walmart. It’s the same pen.

The number is the ball diameter; the line on paper depends on paper and pressure. Jetstream refills also come in 0.38 mm (SXR-38), but we found no US Jetstream RT sold in that size.

What refills does the Jetstream RT use?

It takes the standard Jetstream SXR refill, the same one used in most Jetstream pens.

Ball size	Refill	US 2-pack
0.5 mm	SXR-5	Not found in our sources
0.7 mm	SXR-7	Not found in our sources
1.0 mm	SXR-10	35972 (black), 35973 (blue); uni’s store sells a single black as 133938

unsharpen lists the SXR-7 at 11.2 cm (4.4 in) long. Don’t confuse it with the SXR-600 (a shorter metal refill for G2-style pens) or the SXR-80 multi-pen refill; neither fits the RT. The SXR-80 is the refill for the Jetstream 4&1 multi pen.

Does Jetstream ink smear?

uni-ball markets it as quick-drying and smudge-resistant, and recommends it for left-handed writers, but it doesn’t publish a dry time. Fast drying is the main reason people choose a low-viscosity ballpoint over a gel pen. It’s the maker’s claim; we haven’t timed it.

How does the Jetstream RT compare to the Pilot G2?

Pick the uni-ball Jetstream RT if you smear ink or write left-handed, since its low-viscosity oil-based ink is marketed as quick-drying; pick the Pilot G2 if you want a wetter, more saturated gel line and a finer 0.38 mm tip. The Jetstream RT comes in 0.5, 0.7 and 1.0 mm; the G2 in 0.38, 0.5, 0.7 and 1.0 mm.

	Jetstream RT	Pilot G2
Ink	Low-viscosity oil-based, pigment	Water-based gel
Sizes	0.5 · 0.7 · 1.0 mm	0.38 · 0.5 · 0.7 · 1.0 mm
Refill	SXR-5 / -7 / -10	77232 / 77240 etc. (BLS-G2)
Drying	Marketed as quick-drying	Can smear in 0.7 and 1.0 mm
Made in	Japan (retailer sheets)	Japan (retailer sheets)

If you want a gel pen that dries faster than the G2, the Pentel EnerGel is the usual alternative.

Pilot’s own low-viscosity oil ballpoint, launched in 2008, is the Pilot Acroball; it takes BRFV-10 refills rather than SXR.

How is the Jetstream different from the uni-ball ZENTO?

Both come from Mitsubishi Pencil, but the Jetstream is an oil-based ballpoint and the ZENTO is a water-based rollerball. The Jetstream RT is a cheap, retractable everyday pen sold in multi-packs. The ZENTO Signature is a capped, metal-bodied premium pen with a Japanese list price of ¥3,300 (about US$21).

If you want uni-ball’s Super Ink in a gel pen instead, the Signo 207 is the retractable gel model most often picked for signing checks.

Where is the uni-ball Jetstream RT made?

US business-supplier spec sheets list the Jetstream RT as made in Japan. OnTimeSupplies gives Japan as the country of origin for item 62152 (0.7 mm black), 62153 (0.7 mm blue) and 73834 (1.0 mm red), and Unsharpen agrees. uni’s US store, uni-ball UK and Mitsubishi Pencil’s Japanese site don’t state it, so check the packaging of the pack you buy.

Frequently asked questions

Is the uni-ball Jetstream a gel pen or a ballpoint?

It is a ballpoint. Mitsubishi Pencil classes Jetstream as a low-viscosity oil-based ballpoint; uni-ball's US marketing calls the ink a hybrid because it aims for gel-like smoothness with ballpoint drying speed.

What refill does the Jetstream RT take?

The standard Jetstream SXR refill in the matching size: SXR-5 for 0.5 mm, SXR-7 for 0.7 mm and SXR-10 for 1.0 mm. US office suppliers sell the 1.0 mm refill as a 2-pack, item 35972 in black and 35973 in blue.

Is the Jetstream good for left-handed writers?

uni-ball and its retailers market the quick-drying ink as resisting smudges and suit it to left-handed writers. uni-ball doesn't publish a dry time, and we haven't timed it; a finer 0.5 or 0.7 mm tip lays down less ink than the 1.0 mm.

Where is the uni-ball Jetstream RT made?

US business-supplier spec sheets list Japan as the country of origin for several Jetstream RT items. The brand belongs to Mitsubishi Pencil, a Tokyo-based company.

Is the Jetstream RT really Wirecutter's best pen?

uni's own US store says New York Times Wirecutter has named it a "Top Pick Since 2013" and "the best everyday ballpoint pen". That's the maker quoting Wirecutter; we couldn't open Wirecutter's current page to confirm it.

Is Jetstream ink waterproof?

uni says Jetstream RT ink is its Super Ink, which it markets as resistant to check washing, water, fading and document alteration. Mitsubishi Pencil's Japanese copy says the ink combines pigment with new colorants.

What is the difference between the Jetstream RT and the Jetstream Standard?

Both take the same SXR refill. The RT has a thicker body covered in a rubbery grip, while the Standard is a slimmer pen with a separate grip section. Unsharpen says the RT is sold in Japan as the Jetstream Rubber Body.

Sources (26)

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