BS EN 1303 – Cylinders

European and British standardisation for cylinders for locks

BS EN 1303:2015 – Cylinders for locks

BS EN 1303:2015 classifies cylinders for locks using an 8-digit coding system. A broadly similar classification system is used for other building hardware product standards. Each digit refers to a particular feature of the product measured against the standard’s performance requirements.

Digit 1 – Category of use

One category is identified:
Grade 1: For use by people with a high incentive to exercise care and with a small chance of misuse.

Digit 2 – Durability

Three grades are identified according to the number of test cycles achieved:
Grade 4: 25,000 cycles
Grade 5: 50,000 cycles
Grade 6: 100,000 cycles

Digit 3 – Door mass

One grade is identified:
Grade 0: no requirement

Digit 4 – Fire resistance

Three grades are identified as follows:
Grade 0: Not approved for use on fire resistant / smoke control door assemblies
Grade A: Suitable for use on smoke control door assemblies
Grade B: Suitable for use on fire resistant and smoke control door assemblies

Digit 5 – Safety

One grade is identified:
Grade 0: no requirements

Digit 6 – Corrosion and temperature resistance

Four grades are identified as follows:
Grade 0: No corrosion requirement, no temperature requirement
Grade A: High corrosion resistance, no temperature requirement
Grade B: No corrosion requirement, temperature requirement from –25°C to +65°C
Grade C: High corrosion resistance, temperature requirement from –25°C to +65°C

Note: No distinction is made between the inside and the outside of either the cylinder and/or the door. On completion of the test, the cylinder must operate using a maximum 1.5 Nm torque on the key.

Digit 7 – Key related security

Six grades are identified and the principal requirements are summarised below:

	Grade 1	Grade 2	Grade 3	Grade 4	Grade 5	Grade 6
Minimum number of effective differs	100	300	15,000	30,000	30,000	100,000
Minimum number of movable levers, pins, discs, etc.	2	3	5	5	6	6
Coding on key could disclose combination	Yes	Yes	No	No	No	No
Torque resistance of plug	2.5 Nm	5 Nm	15 Nm	15 Nm	15 Nm	15 Nm

Digit 8 – Attack resistance

Five grades are identified and the principal requirements are summarised below:
Grade 0: No resistance against drilling, no resistance against mechanical attack
Grade A: 3/5 minute resistance against drilling; resistance against mechanical attack except plug / cylinder extraction
Grade B: 5/10 minute resistance against drilling; resistance against mechanical attack except plug / cylinder extraction
Grade C: 3/5 minute resistance against drilling; resistance against mechanical attack
Grade D: 5/10 minute resistance against drilling; resistance against mechanical attack

Source: Door and Hardware Federation (DHF) Best Practise Guide – Cylinder for locks to BS EN 1303