A scientific guide to choosing 2B and HB pencils: an in-depth analysis of writing ergonomics
——Technical innovation of graphite ratio from Yalong pencils

Under the strict requirements of standardized tests and professional drawing, the choice of pencil hardness has changed from empirical judgment to precise decision-making in material science. This article analyzes the physical property differences and application scenarios of 2B and HB pencils based on the ISO 9996 pencil hardness standard and Yalong pencil laboratory data.

1. Materials Science Basis of Pencil Hardness System
Pencil core is made of graphite (colorant) and kaolin (binder) mixed and sintered in proportion, and its hardness grade follows the European EN 558 standard:

– HB (Hard Black): The ratio of graphite to clay is 1:2, and the Mohs hardness is 2.0-2.5

– 2B: The proportion of graphite is increased to 1.5:1, and the Mohs hardness is 1.0-1.5

Yalon pencils use German KRÜLL graphite purification technology to increase the purity of raw materials to 99.97% (the industry average is 99.2%), so that the uniformity of the core particle distribution reaches ±0.3μm, fundamentally eliminating the “grainy scratching” phenomenon of traditional pencils.

2. Handwriting performance comparison experiment (based on Yalong T2000 series test)
In a constant temperature and humidity laboratory environment, we measured the following data:

– Handwriting blackness: Yalong 2B pencil is 96.3% (ISO brightness), Yalong HB pencil is 88.7%
– Friction coefficient: 2B pencil is 0.12μ, HB pencil is 0.28μ
– Fracture strength: 2B pencil is 18.6N/mm², HB pencil is 24.3N/mm²
– Cutting loss rate: 2B pencil is 9.2%, HB pencil is 5.8%

Conclusion:
– 2B pencil achieves ultra-black handwriting through high graphite content, but the fracture resistance is reduced by 23%
– HB pencil is more suitable for high-frequency writing scenarios due to its clay-reinforced structure

3. Ergonomic matching model of application scenarios
1. Standardized test scenario (recommended: Yalong HB-7 test pen)
According to the data from the Examination Center of the Ministry of Education, the recognition rate of optical scanners for carbon areas above 0.5mm² exceeds 99.97%. The Yalong HB pencil uses “gradient pressure sensing technology” to reach the recognition threshold at 1.2N writing pressure, which reduces the force intensity by 40% compared to traditional HB pens, effectively preventing writing fatigue.

2. Art creation scene (recommended: Yalong 2B-Art professional sketch pen)
Yalon 2B pen adopts “layered graphite arrangement, so that a single layer of pen strokes can present 8 levels of grayscale (ordinary 2B only 5 levels). When used with mainstream plastic erasers (such as Faber-Castell), the residual rate is only 0.03g/m², which is 1/3 of the national standard (≤0.1g/m²).

Engineering drawing scene (recommended: Yalong HB-Tech industrial drawing pen)

Line width stability: At a 60° pen holding angle, the wear rate of the Yalong HB pen tip is 0.003mm/hour, ensuring that the line width error of 8 hours of continuous drawing is less than ±0.05mm.

Compatibility with T-squares: Special siloxane coating treatment stabilizes the friction coefficient of the pen shaft between 0.4-0.6 to prevent the drawing tool from slipping.

Technological innovation of Yalong pencils

Core rod coupling technology: Aviation aluminum is used as the core carrier to make the graphite core The expansion coefficient matches the wood shaft by 99.6%, which completely solves the problem of broken pencils caused by seasonal temperature differences (the broken pencil rate of traditional pencils exceeds 12%).

Ecological sustainable design

Pen wood: Use fast-growing birch certified by FSC, which has a carbon footprint 37% lower than pine.

Paint process: Use water-based UV curing coating, and the emission of benzene series is 1/20 of the EU EN71-3 standard.

Ergonomic breakthrough

The “three-stage grip” developed based on the 3D hand database reduces the pressure distribution of the thumb joint to 18kPa (ordinary pencils exceed 35kPa), and the continuous writing comfort time is increased by 2.1 times.

Professional purchase suggestions

Student group

Primary school lower grades: Choose Yalong HB-3 (8.5mm diameter thick pen).

College entrance examination preparation: Yalong HB-7 (GA/T 1028-2022 Examination Stationery Standard).

Designer Group

Architectural Sketch: Yalong 2B-Arch (with 0.3mm spare core bin).

Fashion Design: Yalong HB-Fashion (can be used with thermal erasing system).

Industrial Field

On-site Marking: Yalong HB-Pro (IP54 dustproof and waterproof certification).

Precision Drawing: Yalong 0.5mm Automatic Pencil (integrated with nanographite core technology).

Conclusion

The choice of pencil hardness is essentially an application decision of graphite crystal engineering. Yalong pencils have redefined the technical boundaries of writing tools through material innovation, creating 20 patented technical solutions in the traditional division of 2B and HB. When writing tools and application scenarios are matched at the molecular level, every handwriting will become a carrier of precise expression.