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

Lead Hardness Scale vs. Schmidt Euro Rollerball Refill

Comparing 2 standards across 13 specifications. 13 key differences identified.

Comparing:
Lead Hardness Scale
Schmidt Euro Rollerball Refill

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.

View full Lead Hardness Scale spec sheet →

The Euro-Format Rollerball Refill (standardized under DIN 16554 and defined by the Schmidt Safety Ceramic 888/5888 format) is the industry benchmark for luxury capped liquid-ink rollerball pens. Measuring 110.6 mm in length and 6.2 mm in barrel diameter with a ceramic ball tip, it is utilized across hundreds of fine writing brands.

View full Schmidt Euro Rollerball Refill spec sheet →

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
110.6 ± 0.3 mm (4.35 in)
Barrel Diameter
6.2 ± 0.1 mm (0.244 in)
Tip Collar Diameter
2.5 mm extending 19.5 mm from shoulder
Ball Material
Sintered ceramic ruby ball (0.5 mm Fine, 0.7 mm Medium, 1.0 mm Broad)
Safety Ceramic Venting
Schmidt extended cap-off time technology prevents tip drying for up to 1 year uncapped
Refill Barrel Variants
Schmidt 888 (plastic tube) / Schmidt 5888 (metal casing)
Brand Compatibility
Pelikan, Faber-Castell, Visconti, Kaweco, Retro 51, ACME Studio, OMAS