If you’ve ever looked closely at a hinge, you might have noticed a line of numbers, letters, or symbols stamped into the metal. They may look confusing at first, but they’re not random. These markings are there to give you important information about how the hinge has been tested, where it can be used, and what you can expect from it.
Learning to read hinge markings can save you time, prevent mistakes, and give you confidence that the product in your hand is the right one for the job.
Why Hinges Have Markings
A hinge does more than hold a door in place. In many cases, it’s a safety-critical fitting. It has to carry weight, keep alignment, and sometimes ensure a fire door works correctly in an emergency. That’s why standards exist: to prove the hinge has been tested and meets the right performance criteria.
The most common system you’ll see in the UK is from BS EN 1935:2002, which applies to single-axis hinges. It uses an eight-digit code that tells you about the hinge’s duty level, durability, weight rating, fire performance, corrosion resistance, security, and overall grade.
The 8-Digit Code Explained
Each digit in the BS EN 1935 marking has a specific meaning:
Digit 1: Category of Use
1 = Light duty (residential)
2 = Medium duty
3 = Heavy duty
4 = Severe duty
Digit 2: Durability
Grade 3 = 10,000 cycles (light duty)
Grade 4 = 25,000 cycles (light duty)
Grade 7 = 200,000 cycles (medium–severe duty)
Digit 3: Door Mass (Weight Rating)
Indicates the weight of the door tested with the hinge, from 10kg (Grade 0) up to 160kg (Grade 7).
Digit 4: Fire/Safety Use
0 = Not suitable for fire or smoke doors
1 = Tested and approved for fire/smoke doors
Digit 5: Safety
1 = Meets ‘safety in use’ requirement
Digit 6: Corrosion Resistance
0 = None
1 = Mild
2 = Moderate
3 = High
4 = Very high (marine/industrial)
Digit 7: Security
0 = No defined security
1 = Suitable where security is required
Digit 8: Hinge Grade
Overall performance rating, from Grade 1 (light duty window hinge) to Grade 14 (severe duty door hinge, tested to 200,000 cycles and 160kg).
So in fact, this simple string of numbers packs in a lot of information, once you know what to look for.
Other Markings You Might See
Beyond the BS EN 1935 code, hinges often carry other markings:
- CE or UKCA marks: These prove the hinge has been tested by an approved test house and manufactured under strict quality control. Since 2016, fire door hinges must carry a CE mark to be compliant. In the UK, CE marks remain recognised alongside UKCA marks.
- Manufacturer’s identification: A name, logo, or trademark. This is vital for warranty claims or fire door maintenance, as replacing like-for-like is required for compliance.
- Standard reference: The number of the European or British Standard used for testing.
By law, these markings need to remain visible even after the hinge is fitted, so they’re usually engraved or stamped on the outer face.
Why Hinge Markings Matter
At first glance, it might seem like overkill to have so much detail stamped on a small piece of hardware. But those numbers could protect you from costly mistakes.
- Fit a hinge rated for the wrong door weight, and the door will sag.
- Use a hinge without the right fire rating, and the entire fire door assembly could fail compliance.
- Choose a hinge without corrosion resistance in the wrong environment, and you’ll be replacing it far sooner than you should.
Reading the markings gives you a quick check that the hinge in your hand is fit for the purpose you need.
FAQs about Hinge Markings
Q: What are hinge markings for?
A: They tell you how a hinge has been tested and what it’s suitable for, including duty level, weight capacity, durability, and whether it’s fire rated.
Q: Do all hinges need CE marking?
A: Not all, but hinges for fire doors must be CE marked under the Construction Products Regulation.
Q: How do I know if a hinge is fire-rated?
A: Look at digit 4 of the BS EN 1935 code (it should be “1”), and check for CE marking.
A final Word on Hinge Markings
Decoding hinge markings doesn’t take long, but it makes life a lot easier. Once you know the basics, those numbers and symbols become a ready-made guide to whether the hinge in front of you is the right one.
At Phoenix Hinges, we stock a wide range of CE-marked and BS EN 1935-tested hinges. They’re easy to order online, with clear product details and fast delivery, so you can be confident you’re getting the right hinge for the job.