--- title: "Tombow MONO Hard-Pen Writing Pencil: 3 mm Core, 4B and 6B" canonical: "https://stationerytimes.com/guides/tombow-mono-hard-pen-writing-pencil/" description: "Tombow MONO hard-pen writing pencil explained: a 3 mm ultra-fine core in 4B or 6B for Japanese school penmanship, a box of 12 for 1,452 yen with tax." category: "Pencils" type: "Wood pencil" published: 2026-11-03 updated: 2026-11-03 author: "Ellis Penhale" publisher: "Stationery Times" sources: 1 products: - name: "Tombow MONO hard-pen writing pencil (KM-KKS4B, KM-KKS6B; box of 12)" brand: "Tombow" brand_origin: "Japan" made_in: "Not stated" material: "Wood case with a 3 mm ultra-fine graphite core (Tombow)" price_band: "$ (under $5 per pencil (multi-packs divided by the count), typical US retail, October 2026)" manufacturer: "Tombow Pencil Co., Ltd. (Tokyo)" model: "MONO hard-pen writing pencil" mpn: "KM-KKS4B" url: "https://www.tombow.com/products/mono_calligraphy_pencil/" --- # Tombow MONO Hard-Pen Writing Pencil: 3 mm Core, 4B and 6B > The Tombow MONO hard-pen writing pencil is a school penmanship pencil with an extra-thick 3 mm ultra-fine core, sold in 4B and 6B in a box of 12. Tombow says the thick, dark, strong core makes stopping, flicking and sweeping strokes in Japanese characters look clean. A box costs 1,452 yen with tax (about US$9.19) in Japan. - URL: https://stationerytimes.com/guides/tombow-mono-hard-pen-writing-pencil/ - Category: Pencils - Author: Ellis Penhale - Published: 2026-11-03 - Updated: 2026-11-03 ![Tombow MONO hard-pen writing pencil: a blue hexagonal barrel with a sharpened wood tip and a white end band](https://stationerytimes.com/images/raster/tombow-mono-hard-pen-writing-pencil-illustration-16x9.png?v=d466f4ed) *The hard-pen writing pencil, drawn in proportion (Tombow lists no length); circle: the 3 mm core, 1 mm = 24 px.* Original illustration made for this guide. © Stationery Times. Original drawing (SVG): . Drawings © 2026 Stationery Times, reusable with credit under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ## Product facts | Product | Brand | Brand origin | Made in | Material | Released | Price range (typical US retail, October 2026) | |---|---|---|---|---|---|---| | Tombow MONO hard-pen writing pencil (KM-KKS4B, KM-KKS6B; box of 12) | Tombow (by Tombow Pencil Co., Ltd. (Tokyo)) | Japan | Not stated | Wood case with a 3 mm ultra-fine graphite core (Tombow) | – | $: under $5 per pencil (multi-packs divided by the count) | - Made in (Tombow MONO hard-pen writing pencil (KM-KKS4B, KM-KKS6B; box of 12)): Not stated. Tombow's Japanese product page lists grades, the box and the price but no country of manufacture. Check the box. ## Key takeaways - Tombow gives the core diameter as 3 mm, thicker than a general pencil's, to vary line strength easily. - It comes in two grades, 4B (KM-KKS4B) and 6B (KM-KKS6B), in a box of 12 hexagonal pencils. - Tombow says the ultra-fine core is smooth, strong, dark and hard to break, and renders tome, hane and harai strokes cleanly. - A box costs 1,452 yen with tax (about US$9.19), or 1,320 yen before tax, about 121 yen (about US$0.77) a pencil. - Tombow's page gives no pencil length, diameter or country of manufacture. ## What is the Tombow MONO hard-pen writing pencil? **It is a thick, soft pencil made for Japanese school penmanship.** Tombow's page says its ultra-fine core is extra thick at 3 mm, smooth, strong and dark, and that it renders the stop, flick and sweep strokes of Japanese characters cleanly. Tombow sells it in two soft grades, 4B and 6B. It belongs to the [MONO](https://stationerytimes.com/guides/tombow-mono-pencil/) family. We read Tombow's Japanese product page on November 3, 2026. ## Why a 3 mm core? **To make line strength easy to control.** Tombow says the 3 mm core is thicker than a general pencil's, so you can vary pressure and strength more easily. That helps with the stroke endings, tome (stop), hane (flick) and harai (sweep), that Japanese penmanship teaches. Tombow does not give a general-pencil core size to compare, so we don't either. ## Which grade should you buy? **4B or 6B, both soft and dark.** | Grade | Model | Pack | Price with tax | |---|---|---|---| | 4B | KM-KKS4B | 12 hexagonal pencils | 1,452 yen (about US$9.19) | | 6B | KM-KKS6B | 12 hexagonal pencils | 1,452 yen (about US$9.19) | Tombow also lists 1,320 yen before tax. A box works out to about 121 yen (about US$0.77) a pencil, our arithmetic. Tombow leaves the choice to taste. ## How does it compare with the MONO pencil? **Same ultra-fine core technology, a different job.** Tombow's pages describe the same dense core, smooth, dark and hard to break, in both pencils. The difference is in the shape and grades. | | Hard-pen writing pencil | [MONO](https://stationerytimes.com/guides/tombow-mono-pencil/) | |---|---|---| | Core | 3 mm, extra thick | Size not stated | | Grades | 4B and 6B | 12, from 4H to 6B | | Made for | Japanese school penmanship | Drafting and drawing | | Box of 12 with tax | 1,452 yen (about US$9.19) | 1,320 yen (about US$8.35), eraser included | The hard-pen pencil costs about 132 yen (about US$0.84) more per box, and Tombow's page does not list an included eraser for it. ## What do the stroke names mean? **They are the three ways a line can end in Japanese writing.** Tombow names them on its page. Tome is a stop, where the stroke ends firmly; hane is a flick, where the end springs away; harai is a sweep, where the stroke trails off. A thick, dark, soft core makes the differences in pressure show, which is the reason Tombow gives for the 3 mm size and the 4B and 6B grades. ## Who is the hard-pen writing pencil for? **It suits learners practicing bold Japanese characters and anyone who wants a thick, soft, dark pencil line.** Tombow gives a 3 mm core in 4B and 6B, made for the stop, flick and sweep strokes of Japanese penmanship. Skip it for general note-taking or fine drawing: the 3 mm core and soft grades are for bold strokes. For writing pencils see our [best wooden pencils for writing](https://stationerytimes.com/guides/best-wooden-pencils-for-writing/), and for grade scales [pencil grades explained](https://stationerytimes.com/guides/pencil-grades-explained/). ## What should you watch out for? **Use it only for writing.** Tombow's single caution is that the pencil is not for any other use. A thick core needs a sharpener that takes it; Tombow's page does not recommend one. ## Where is it made, and what does it cost? **Tombow's page doesn't state a country of manufacture.** At 1,452 yen with tax for 12 (about US$9.19), a pencil is about US$0.77, in our $ band (under $5 a pencil). ## Frequently asked questions ### What is hard-pen writing? Hard-pen writing, koohitsu shosha in Japanese, is penmanship practice with a pencil or pen rather than a brush. Tombow made this pencil for it. ### How thick is the core? 3 mm, which Tombow says is thicker than the core of a general pencil, so line strength is easy to vary. ### What grades are sold? 4B (KM-KKS4B) and 6B (KM-KKS6B). ### What strokes does it suit? Tombow says the thick, dark core renders tome (stop), hane (flick) and harai (sweep) strokes cleanly, the strokes of Japanese character writing. ### What is the core like? Tombow says it is an ultra-fine, high-density core that writes smooth and dark, fixes to paper well and does not break easily. ### How many come in a box? Twelve hexagonal pencils. ### How much does it cost? 1,452 yen with tax (about US$9.19) a box in Japan, 1,320 yen before tax, about 121 yen (about US$0.77) a pencil. ### Where is it made? Tombow's page doesn't say; check the box. ## Sources - [Tombow (Japanese): MONO hard-pen writing pencil product page (3 mm core, 4B and 6B, stroke claims, models, price; read November 3, 2026)](https://www.tombow.com/products/mono_calligraphy_pencil/)