The Technology

The success of the AutoStem Cartridge is a result of the harmless gas generation and ease of use during rock breaking, drilling and blasting.

Unique features include:


The cartridge stems itself. Use requires no additional stemming effort by the operator. It is the world’s only drop-and-go cartridge.

The AutoStem range is accompanied by a range of booster cartridges, enabling the operator to easily increase his charge.
Water tightness

Ensures efficiency in water clogged boreholes and in wet conditions
Vertical and horizontal holes
Cartridges can be used in any orientation, suitable for above and underground work

How it works

The AutoStem Cartridge requires no stemming and is simply dropped into a borehole by the operator. The initiating wire is then connected to the blaster’s firing cable and initiated by a conventional shot firer.

When initiated in a borehole, the proprietary compound in the cartridge ignites to produce high volumes of harmless gas at very high pressures. This gas then works against the rock from within the borehole, which is automatically stemmed by the actuation of the built-in stemming mechanism of the AutoStem Cartridge, causing fracturing, breaking and heaving of the rock (or concrete) structure.

When initiated in an unconfined environment, due to a lack in pressure build-up, the proprietary compound contained within the AutoStem Cartridge will not undergo its combustion reaction, rendering the AutoStem Cartridge entirely harmless if not used within a borehole.

A clearing area of 20m – 50m is recommended (there is minimal throw rock with the AutoStem Cartridge), and the rock can be immediately re-approached because there are no harmful gasses.

Non-Detonating Solutions (Pty) Ltd also supplies the AutoStem booster, which is a supplementary cartridge (of 60g or 100g), which can be used in conjunction with the AutoStem Cartridge in a borehole, to augment the total charge delivered to the rock. This simple application makes the AutoStem Cartridge very user friendly, leaving the end-result achievable completely up to the operator.


The AutoStem Cartridge offers unparalleled safety. Because the cartridges do not detonate, there is no fire, flame, spark or explosion caused. Classified by the United Nations under either UN 0323 and UN 0432, these cartridges are deemed safe for transport, even on a passenger airplane, and have a shelf life of 18 months.

Unlike conventional explosives, the AutoStem Cartridge emits no shockwave on initiation, which means that there is no potential for damage to existing surrounding structures, equipment or on-site personal. Because the initiation is very controlled, there is no flying rock, dust or harmful emissions.

Frontiers of research

Mechanical engineers are constantly pushing the boundaries of what is physically possible in order to produce safer, cheaper, and more efficient machines and mechanical systems. Some technologies at the cutting edge of mechanical engineering are listed below.

AutoStem is well suited for narrow-reef mining operations in underground mines, and for rock breaking of all types in sensitive areas because: There are no shockwaves – the cartridge does not compromise hanging wall and footwall conditions, so no overbreak is created. It is extremely safe, meaning handling and storage poses no site-risk. There is no pulverisation of high value commodity – improving yield and fragmentation size consistency in the blasting process. Continuous mining is a reality – you only need a minimal clearing area and no harmful gasses are released. Suitable for coal mining – large masses of coal can be dislocated with almost no loss in the form of fines and/ or dust. Most cost effective secondary breaking solution AutoStem is also an attractive option in quarrying operations, for all secondary breaking requirements, and in low-height benching work. No clearing area is required– there is no downtime when drilling and blasting. There is no flyrock- equipment does not have to be removed and rock breaking can occur in sensitive areas without ground shock.

AutoStem is great for tunnelling as: Tunnelling can be carried out on a continuous basis – without compromising the structural walls of the tunnel. Ventilation and clearing demands are drastically reduced. There is no vibration – which is key in sensitive areas. Minimal risk of fly rock.

AutoStem is very well tailored for civil demolition and mass excavation works: Blasting can occur all day with minimal cover and no flyrock. No shockwave vibration – so no removal of heavy equipment is required. This makes AutoStem perfect for in-city rock breaking applications, especially where low vibration readings (PPV) is a requirement. In addition, Suitable for residential rock breaking where vibration, flyrock and gasses are not at all tolerable by the surrounding community. Various cartridges sizes make various burden and spacing patterns achievable in all types of concrete and rock. Suitable for rock and concrete cutting close to water supply pipes, fuel lines etc. Suitable for delicate rescue work underground or in collapsed concrete structures.

AutoStem cartridges can be used up to 40m underwater for rock and concrete breaking: No shockwaves are caused – so there is no disruption to ports or harbours. Very limited impact on sea life. Sequential blasting is possible – this radically reduces blasting time and construction/ demolition costs.

AutoStem suitable for embedded rock Continuous trenching is achievable. No requirement to remove equipment during blasting cycle.

AutoStem can be used for all general rock breaking applications: Without the onerous demands and limitations of conventional high explosives Without the cost and time consuming nature of conventional mechanical breakers