There are ways to combat every type of attack that can be applied to a safe.
- Moving it is the most simple mode of attack. To prevent this, the safe must be as heavy as practical, be attached as well as possible to the structure in which is housed, and have no access points for lifting devices.
- Blasting: The principles of steel reinforcing are applied, where “re-bar” has good tensile strength and concrete has good compressive strength. There must not be access holes for dynamite, and drilling of holes must be as difficult as possible.
- Drilling: The material must be a composite of mineral and steel. The mineral component defeats a steel drill and the steel defeats a carbide drill. The addition of porcelain balls is highly beneficial to defeat both steel and carbide drill tips. Balls are seldom contacted head on so the drill is also deflected. Corundum, with a hardness of 9 on the Moh Scale is a popular aggregate. The addition of a bit silicon carbide, 9,5 on the Moh Scale really messes up drills. Fine zirconia toughened alumina balls are very resistant to drilling and grinding.
- Grinding: The same principles apply as for drilling. The addition of sulphur helps. It melts and lubricates the blade. It also gives off nasty fumes. Aluminium chips clog up a blade.
- Thermal lancing: Portland cement is replaced by calcium aluminate cement which has a very high melting point. Use corundum aggregate with a melting point of 2013°C. A high thermal mass aggregate helps a lot, as it absorbs the heat. Pizza Oven Floor mix is designed for high thermal mass, and is also very heavy. If plastic packets of thermit powder are added to the mix they will endanger the life of the burglar, but also create a serious fire hazard.
- Impact: Keracomp is a composite of ceramic and steel fibres which is almost indestructable by impact.