Lead Hardness Scale vs. Parker G2 Refill
Comparing 2 standards across 13 specifications. 13 key differences identified.
The Graphite Hardness Grading Scale (standardized under ISO 15184 and ASTM D3363) classifies pencil graphite from 9H (hardest, lightest grey, highest clay content) through HB (medium equilibrium) to 9B (softest, darkest black, highest graphite content). HB is the universal writing standard and the exact equivalent to the North American No. 2 pencil.
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.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Hard Grade Range (9H to 2H)
|
9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H — high clay/polymer binder ratio, crisp hairline precision, zero smudging | — |
|
Medium Equilibrium Range (H, F, HB, B)
|
H (Hard), F (Fine point retention), HB (Hard Black — standard writing balance), B (Black) | — |
|
Soft Grade Range (2B to 9B)
|
2B, 3B, 4B, 5B, 6B, 7B, 8B, 9B — high graphite content, deep velvety blacks, artistic shading | — |
|
US No. 2 Pencil Equivalent
|
HB grade (mandatory for optical Scantron standardized bubble test optical scanners) | — |
|
US Numbering System Cross-Check
|
#1 = B | #2 = HB | #2.5 = F | #3 = H | #4 = 2H | — |
|
Origin
|
Developed by Joseph Hardtmuth of Koh-i-Noor in Vienna (1790s), who introduced the H/B alphanumeric system | — |
|
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 |