Understanding core drilling standards to improve security storage protection

As security threats evolve, so should the solutions designed to combat them. One such evolution is the use of core drilling by criminals to access safes and strong rooms. In just a few decades, core drilling has transformed from a useful and productive tool within the construction industry to a highly dangerous addition in a thieves’ toolkit. For organisations looking to protect high-value assets, understanding the history and threat of core drilling will enable you to choose the right, certified security solutions.  

The background of core drilling standards

Core drilling is essentially a method used to drill and extract circular holes within solid, reinforced materials. One of the key benefits of core drilling is that it produces little noise and minimal vibration. However, since its introduction in the 1970s, it took until the 1980’s for people to realise how core drilling could be used to force entry. At this time, safes and strongrooms were designed and constructed under specific standards that tested against cutting, drilling, breaking and thermal tools, secure storage units of this time simply weren’t equipped to protect against core drilling.  

It started to change in 2002 due to the growth of core drilling attacks. Optional testing, a described method and certifications were introduced for strong rooms under the EN 1143-1 standard; testing for safes followed in 2005. Today, core drilling is now used within the ‘general testing’ tool list under T2 certifications, but to obtain a Core Drilling (CD) Rating, a dedicated test must be performed under a separate set of performance criteria. 

The difference between safe and strong room protection

When you’re considering which secure storage to choose, it’s important to recognise if the product has been tested to the right criteria under EN 1143-1, as it differs across safes and strong rooms.  

When it comes to safes, core drill testing focuses on how long they can resist attack. Independent testers may attempt to drill a hole large enough to remove the contents by hand, a 125mm diameter hole, with core drilling typically limited to a diameter of up to 150 mm. In contrast, testing for strong rooms and doors is based on a different objective: preventing or significantly delaying forced entry rather than allowing access through contained extraction methods. 

When testing strongrooms, the aim is to try and make a hole sufficiently big enough to enable a person to pass through. Under the testing criteria, from a minimum of 325mm in diameter, up to 400mm.. In addition, higher security strong rooms are also subjected to attacks with more powerful machines. 

Why should you choose CD rated products

CD testing reflects the real-world attack methods being used today; it isn’t all about brute force, it’s about precision, control and power. In late 2025, a German high-street bank in Gelsenkirchen was targeted by thieves using heavy drilling equipment. The culprits were able to penetrate a vault wall and access thousands of safe deposit boxes. With an estimated loss of €100 million, local police likened it to a scene from Ocean’s Eleven.  

This case really emphasises the importance of going above and beyond with your security, and choosing only the best, certified solutions to prevent this from happening again. The additional CD test will grant you that further layer of assurance if faced with conventional or sophisticated attacks. CD testing, alongside T2 standard testing, will also comply with enhanced insurance policies and provide you with complete confidence that you and your assets are protected.  

Consider layered security with Gunnebo Safe Storage.

Security must be part of a complex infrastructure if you want to deter or stop thieves from accessing your safes or strong rooms. Planar protection is our way of delivering an alarm matrix that is integrated into your safe, strong room, door or vault panel; this alarm system will activate should any forced entry be detected. 

We have a collection of safes and strong rooms that are highly resistant to burglars, sophisticated tools, fire and explosives, all with the added option to include an alarm wiring matrix. The Triforce T2 high-graded safe is an industry-first solution. With its EN 1143-1 standard certification compliance, the option of core drill protection testing and planar protection, and its continual resistance to fire makes this a stand-out, resilient and highly secure solution.  

We also offer our Centurion SR strong room. This solution is tested to T2 security standards as well as advanced testing for core drilling and explosives. The Centurion guarantees the highest level of performance under physical security standards and does come with the additional option to add integrated alarms.  

Each of our products is designed and tested to meet the varying levels of operational need and risks within your home or business. Our range of safes, strong rooms and doors, and cast in-situ reinforcements are built to stand up to current and emerging threats.  

If you’d like to learn more about CD rating and testing, head to our website, or get in touch with a member of our team.