Mechanical Pencil Leads vs. Fountain Pen Cartridges
Comparing 2 standards across 13 specifications. 13 key differences identified.
Mechanical Pencil Lead Sizes (standardized under ISO 9177-2) define polymer-bonded graphite refill diameters: 0.2 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, and 2.0 mm leadholders, with a standard length of 60.0 mm. Sized for specific drafting and handwriting pressures, 0.5 mm is the universal drafting standard and 0.7 mm is the heavy-pressure writing standard.
Proprietary Fountain Pen Cartridges are brand-exclusive ink formats engineered with unique nozzle diameters and collar locking geometries that are incompatible with Standard International pens. Key proprietary systems include Pilot/Namiki (wide 5.5 mm bore), Lamy T10 (stepped collar), Sailor (flared collar), and Platinum (metal ball seal).
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
0.2 mm Lead (Pentel Orenz)
|
0.20 mm — ultra-micro drafting and mathematical annotation (requires sliding guide pipe) | — |
|
0.3 mm Lead (Drafting)
|
0.35 mm actual diameter — technical engineering drafting, complex kanji, fine stippling | — |
|
0.5 mm Lead (Universal)
|
0.50 mm actual diameter — the global standard for students, drafting, and office writing | — |
|
0.7 mm Lead (Heavy Pressure)
|
0.70 mm actual diameter — robust everyday writing, resists snapping under heavy hand pressure | — |
|
0.9 mm Lead / 1.3 mm Lead
|
0.90 mm to 1.30 mm — woodworking carpentry, standardized test bubble filling, primary school | — |
|
2.0 mm Leadholder (Clutch Pencil)
|
2.00 mm diameter × 130 mm length — architectural sketching, requires rotary lead pointer sharpener | — |
|
Standard Refill Length
|
60.0 ± 1.0 mm (for 0.2 mm to 0.9 mm polymer high-polymer leads) | — |
|
Pilot / Namiki Cartridge
|
— | Length: 59.0 mm | Wide 5.5 mm bore | Capacity: ~0.90 ml (IC-50 / IC-100 / Parallel) |
|
Lamy T10 Cartridge
|
— | Length: 68.0 mm | Stepped friction collar | Capacity: ~1.15 ml (Lamy Safari, 2000, Studio) |
|
Sailor Proprietary Cartridge
|
— | Length: 48.0 mm | Flared ribbed collar | Capacity: ~1.00 ml (Sailor 1911, Pro Gear) |
|
Platinum Proprietary Cartridge
|
— | Length: 65.0 mm | Metal stainless steel sealing ball | Capacity: ~1.20 ml (Century #3776, Preppy) |
|
Parker Quink Cartridge
|
— | Length: 76.0 mm | Stepped friction plug with reserve tank | Capacity: ~1.20 ml |
|
Cross Cartridge
|
— | Length: 38.0 mm | Narrow tapered mouth (Classic Century vs Townsend / Peerless) |