What is the BS EN 12320 Padlock Grade?

BS EN 12320 is a British Standard that provides a grading system for padlocks. It is closely based on the European CEN standard, which tests padlocks for resistance to cutting, sawing, twisting, pulling and other attack methods. In simple terms, BS EN 12320 is a UK-aligned version of the CEN grading model.

How The Grading Works

The BS EN 12320 grade appears as a two-number code. For example: BS EN 12320-34
The first number refers to the padlock’s weather resistance. The second number refers to its security grade, which matches the CEN scale from 1 to 6 (1 being low security, 6 being high security).

CEN Security Grading

Grade 1: Low security, light domestic use
Grade 2: General use, low-risk environments
Grade 3: Medium security, sheds and gates
Grade 4: High security, commercial sites
Grade 5: Very high security, industrial applications
Grade 6: Maximum security, heavy-duty and professional use

Weather Resistance Ratings

This is where BS EN 12320 is less consistent. The weather rating simply states whether the padlock is suitable for indoor or outdoor use. There is no robust testing protocol behind this element, and manufacturers assign this value themselves. As a result, it should not be relied upon when choosing a padlock for harsh environments.

What Happens In Practice

If you choose a padlock with a CEN Grade of 3 or higher, it will automatically meet or exceed BS EN 12320 security expectations. Therefore, focusing on the CEN security grade is usually the most reliable way to select a high-security padlock.

When To Choose A BS EN 12320 Padlock

When an insurer or building specification explicitly asks for it
When purchasing for commercial or regulated environments
When needing documented compliance for site audits

When To Focus On CEN Grade Instead

When real-world security performance is your priority
When selecting padlocks for warehouses, gates, roller shutters or containers
When evaluating hardened steel vs stainless weatherproof models

Simple Recommendation

If you are asked for a BS EN 12320 approved padlock:
Choose a CEN Grade 3 or higher, and optionally a closed shackle style for added protection.