# item.guide
Side-by-Side Comparison Pens, Inks & Leads

Parker G2 Refill vs. Mechanical Pencil Leads

Comparing 2 standards across 14 specifications. 14 key differences identified.

Comparing:
Parker G2 Refill
Mechanical Pencil Leads

The Parker-Style G2 Refill (standardized under ISO 12757-2 Doc G2) is one of the most widely adopted ballpoint and gel pen refill standards. Measuring 98.1 mm in length and 5.8 mm in body diameter with a stepped metal barrel and grooved plastic crown cog, it is used by hundreds of luxury pen brands and custom machined EDC pens.

View full Parker G2 Refill spec sheet →

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.

View full Mechanical Pencil Leads spec sheet →

Specification Comparison Table

14 Parameters
Parameter / Spec
Overall Length
98.1 ± 0.3 mm (3.86 in)
Main Body Diameter
5.8 ± 0.1 mm (0.228 in)
Stepped Tip Diameter
2.5 mm extending 18.0 mm from barrel shoulder
ISO Standard Code
ISO 12757-2 Type G2 (Documentary permanence proof)
Crown Cam Geometry
Molded nylon cog crown with 4 radial guide splines for push-button advance mechanisms
Available Ink Formulations
Oil-based ballpoint (Parker QuinkFlow, Schmidt P900), hybrid low-viscosity (Uni Jetstream SXR-600), gel ink (Schneider Gelion+, Itoya)
Pen Brand Compatibility
Parker, Pelikan, Faber-Castell, Rotring (600/800), Retro 51 Tornado, Tactile Turn, Karas Kustoms
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)