---
term: "Blaine Fineness"
category: "testing-analysis-systems"
shortDefinition: "Cement fineness index from air permeability through a packed powder bed, expressed as Blaine specific surface area (m²/kg) per EN 196-6 or ASTM C204."
formula: "S = (K/ρ)·(√e³/(1−e))·(√t/√(0.1η)); simplified: S = (524.2·K/ρ)·√t"
relatedStandards: ["EN 196-6","ASTM C204"]
url: "https://vectorbtc.com.tr/resources/glossary/blaine-fineness/"
---

## What it measures

**Blaine fineness** correlates **specific surface area** of cement (or similar powders) with **air flow resistance** through a compacted bed. Finer grinding increases surface area and typically accelerates early hydration.

## How it is tested

A **Blaine permeability cell** is filled and compacted; air flow and pressure drop are measured and converted to specific surface using a calibration constant tied to reference cement.

## Standards and reporting

[EN 196-6](/resources/standards/en-196-6/) and [ASTM C204](/resources/standards/astm-c204/) define apparatus, bed preparation, and calculation. Report temperature, manometric liquid, and reference cement used for calibration.

## Common errors

Poor bed compaction, moisture in powder, and drifted permeability cell constants produce inconsistent Blaine values across shifts. When Blaine is inconclusive for ultrafine cement, **EN 196-6** air-jet sieving (e.g. [Alpine air jet sieve](/products/sieving-systems/air-jet-sieve-systems/alpine-air-jet-sieve/)) may be required.