Question 1

1. What is a 7n concrete block?

Accepted Answer

A 7n concrete block is defined by a minimum compressive strength of around 7 newtons per square millimetre (7 N/mm²). It meets BS EN 771-3 standards and comes in solid or hollow forms, with typical dimensions 440 mm long by 215 mm high, and thicknesses of 75 mm, 100 mm or 140 mm.

Question 2

2. Are 7n concrete blocks different from 7.3 n blocks?

Accepted Answer

In practice, “7n” and “7.3 n” descriptions refer to similar compressive strength - 7.3 N/mm² is a more precise figure found in many dense concrete blocks. This minor difference has minimal impact on suitability, unless project specs call for exact strength values.

Question 3

3. What does the ‘N’ stand for on a 7n concrete block?

Accepted Answer

The ‘N’ stands for newtons, which is a unit of force. It refers to the compressive strength of the block, measured in N/mm². A 7n concrete block can withstand around 7 newtons per square millimetre before failure.

7n concrete blocks

Solid Dense Concrete Block 7.3N 100mm

Hollow Dense Concrete Block 7.3N 215mm

Thermalite Solid Hi-Strength Block 7.3N 100mm

Solid Dense Concrete Block 7.3N 140mm

Plasmor Stranlite Concrete Block 7.3N 100mm

H+H Celcon Solid Hi-Strength Block 7.3N 100mm

CCP Modulite Solid Medium Dense Concrete Block 7.3N 100mm

Thermalite Hi-strength Block 7.3N 140mm

Tarmac Concrete Block Topcrete Standard Solid Block 7.3N 440 x 100 x 215mm

Forterra Fenlite Solid Lightweight Concrete Block 7.3N 100mm

Interfuse Intercrete Solid Dense Concrete Block 7.N 140mm

Lightweight Solid 7.3N Block 440 X 215 X 140 mm

Plasmor Fibolite Solid Lightweight Concrete Block 7.3N 100mm

Tarmac Topcrete Solid Dense Concrete Block 7.3N 140mm

PLASMOR COURSING 100mm BRICK 7N

Hi-strength Thermalite Trench Blocks 7.3N 300mm

Thermalite Hi-strength Block 7.3N 215mm

CCP HOLLOW CONSOLITE DENSE BLOCK 215mm 7.3N 353910

Tarmac Topcrete Hollow Concrete Block 7.3N 140mm

Tarmac Topcrete Hollow Concrete Block 7.3N 215mm

Stowell Hollow Concrete Block 7.3N 215mm

Tarmac Concrete Block Hemelite Standard Solid Block 7.3N 440 x 140 x 215mm

Besblock 100mm Insulite Medium Density Solid 7.3N

FORTERRA Evalast Solid Dense Block 7.3N 440 x 215 x 100mm

Newlay Newcon Solid Dense Block 7.3N 440 x 215 x 100mm