Compiled from 1 sources; we haven't tested this product ourselves yet. How we research
Quick answer
The Tombow MONO Work is a 1.3 mm thick-lead mechanical pencil made for filling mark-sheet exam bubbles fast and dark. It has a 5.3 mm twist-out MONO eraser, a 40 mm non-slip rubber grip, a short rubber knock and a plain barrel with no English lettering. It costs 594 yen with tax (about US$3.76) in Japan.
$under $5 per pencil (multi-packs divided by the count)
Colors
Mono color
Rate it
No ratings yet. Be the first to rate this product.
Notes on these facts
Made by Tombow Pencil Co., Ltd. (Tokyo). Country of manufacture not stated: Tombow's Japanese product page lists model numbers, colors and prices but no country of manufacture, so check the label on your copy. Price: example listing.
Colors: names per Tombow (Japan), checked November 2, 2026. Tombow lists five plain-barrel colors: Mono color (DPB-151A), Smoke (DPB-151B), White (DPB-151C), Green (DPB-151D) and Pink (DPB-151E). Tints were sampled from Tombow's product images and are representative, not measured. Tints are representative, not measured. Shops stock different colors.
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 = CZK 21.7; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).
Key takeaways
The lead is 1.3 mm; Tombow's own test says filling 200 mark-sheet bubbles took 466 seconds against 620 seconds with a 0.5 mm lead.
The twist-out MONO eraser is 5.3 mm across, and the rubber grip is 40 mm long, per Tombow.
Five plain barrel colors are sold: Mono color, Smoke, White, Green and Pink, at 594 yen with tax (about US$3.76).
Replacement HB or B leads (8 per pack) cost 220 yen (about US$1.39), and a pencil-plus-HB-lead set is 814 yen (about US$5.15).
Tombow warns that some exams specify the writing tool, so check the rules before using it.
What is the Tombow MONO Work?
It is a 1.3 mm mechanical pencil Tombow pitches as thick, fast and dark. Tombow says the thick lead writes quickly and clearly, erases well, and is the best choice for mark-sheet tests, while also being useful for notes and ideas. It borrows the twist-out MONO eraser from the MONO Graph family. We read Tombow’s Japanese product page on November 2, 2026.
What are the features?
A thick lead, a pinpoint eraser and a grippy, plain body. Tombow lists these.
1.3 mm high-performance lead. Thick, dark and tough, with good erasability.
Twist-out MONO eraser. A 5.3 mm eraser suited to pinpoint corrections.
Non-slip rubber grip. The grip is 40 mm long.
Short rubber knock. The knock button is rubber, short so it rarely touches your hand, and it doubles as a roll stopper.
Plain barrel in five colors. There is no English lettering on it, a design Tombow says is safe to use in an exam hall.
Is a 1.3 mm lead really faster for mark sheets?
Tombow says so, from its own test. It reports filling 200 bubbles in 466 seconds with the MONO Work against 620 seconds with a 0.5 mm lead, from a monitor test of 30 people, and calls that 2 minutes 40 seconds faster. By our arithmetic the gap is 154 seconds (2 minutes 34 seconds). The method is not published, so treat it as a maker claim; the thick line does cover more of a bubble per stroke.
Which color and refill should you buy?
Any of five colors, all 594 yen. Tombow lists these.
Item
Model
Price with tax
Pencil: Mono color, Smoke, White, Green, Pink
DPB-151A to E
594 yen (about US$3.76)
Lead, HB or B, 8 leads
ECJ-121 (HB), ECJ-120 (B)
220 yen (about US$1.39)
Set: Mono color pencil with HB lead
PCB-251
814 yen (about US$5.15)
Replacement eraser, three
ER-MG
132 yen (about US$0.84)
Who is the MONO Work for?
It suits test-takers and fast note-takers who want one bold, thick line.
Everyday writing: Tombow lists it at 594 yen with tax (about US$3.76), in the $ band, with 1.3 mm lead refills at 220 yen (about US$1.39) for eight.
Skip it for small handwriting: a 1.3 mm lead is far thicker than a 0.5 mm one. For finer writing see the MONOgraph Fine or our best mechanical pencils.
How do you refill it?
Pull the eraser unit out to add lead. Fill from the back, up to about four leads. When the eraser falls out on its own, pull it out leaving enough to pinch, push in a new ER-MG and turn the unit counterclockwise. Tombow says to extend the eraser only 3 to 4 mm.
What should you watch out for?
Check your exam’s rules and keep the card. Tombow says some exams specify the writing tool and may not allow it, and because the pencil has no name or number printed, you should keep the backing card. A dropped pencil can bend the tip pipe, which can break lead or stop feeding. Keep it from small children.
Where is it made, and what does it cost?
Tombow’s page doesn’t state a country of manufacture. At 594 yen with tax (about US$3.76), the pencil is in our $ band (under $5).
Frequently asked questions
What is the MONO Work for?
Tombow says it is made for mark-sheet exams, where a thick lead fills bubbles fast, and for jotting notes and ideas.
How much faster is a 1.3 mm lead?
Tombow says 200 bubbles took 466 seconds against 620 seconds with a 0.5 mm lead, in a 30-person monitor test. That is a gap of 154 seconds by our arithmetic, which Tombow rounds to 2 minutes 40 seconds.
What lead does it take?
1.3 mm only. Tombow sells HB (ECJ-121) and B (ECJ-120) in packs of eight.
What colors are sold?
Mono color, Smoke, White, Green and Pink, per Tombow.
Does it have an eraser?
Yes, a twist-out MONO eraser 5.3 mm across, suited to pinpoint erasing. Replacements are ER-MG, three for 132 yen (about US$0.84).
Why is the barrel plain?
Tombow says the simple barrel with no English lettering is meant to be safe in an exam hall. Because nothing is printed on it, Tombow suggests keeping the backing card for the model name and number.
Can I use it in any exam?
Not necessarily. Tombow says some exams specify the writing tool, so check the rules.
Where is it made?
Tombow's page doesn't say; check the label on your copy.
