As is known in practice, handling hand tools in certain work environments can be very dangerous. This statement does not refer to the correct handling of the tools themselves to avoid personal accidents, but to the surrounding conditions in the work environment and/or the risk posed by the contact of a tool with some element found in that environment.
Thus, for example, electricians, technicians and anyone who works with electrical or electronic systems know the great advantages of insulated tools, as well as the safety they offer when handling cables, connections and energized objects.
In the same way, gas technicians and other workers who carry out tasks in flammable environments or where vapors, liquids, dusts or combustible residues that entail a potential risk of explosion are present, also have a wide range of safety tools: they are the so-called non-sparking tools.
What is a non-sparking tool?
First of all, we must make a clarification of concepts. In general, the handling of all hand tools produce sparks. Commonly used hand tools are often made of steel. They can cause ignition by friction, either by impact with each other or with other materials such as steel or concrete, in which a mechanical or frictional spark is generated. They can also ignite through a chemically generated spark from the impact between certain metals and some oxygen-containing substances (such as rust, which is iron oxide). This means, therefore, that the presence of sparks is common in any work environment.
However, if that environment is also explosive or flammable, the production of sparks could be fatal. Some examples of this type of environment can be found in the chemical, automotive, oil, paper, pharmaceutical, mining, pyrotechnic, nuclear, agricultural, railway, aeronautical, weapons, food and many other industries. The presence of explosive environments is also common in public service companies such as gas, electricity and telecommunications, treatment of wastewater and hazardous waste, fire stations, military bases and many others.
Actually, the non-sparking tools as they are known in the market they also generate sparks, known in the industry as “cold sparks”. The peculiarity is that these cold sparks receive that name because they have a low calorific level and do not ignite carbon disulfide, which is the substance that has the lowest known self-ignition point and barely reaches 90ºC. Therefore, while non-sparking tools can reduce the risk of sparking, they do not eliminate the possibility of a spark.
With this we verify that the denomination “anti-spark tool” is misleading, since these tools are capable of producing a spark. A more suitable term would be, for example, “tools with reduced spark formation”. However, the erroneous expression gained a lot of ground in the market and at this point it is difficult to eradicate it.
The important thing is not only to keep this clarification in mind, but also to consult the manufacturer of the tool and the supplier of the flammable material, for example, to obtain more information, follow their recommendations and ensure that we work in an environment that is as safe as possible.
What materials make up a non-sparking tool?
Non-sparking tools are made from metal alloys. The most common are copper-beryllium (CuBe2) and aluminum-bronze (AlBr) alloys, which do not produce dangerous sparks when struck.
CuBe2 tools are generally composed of 96% copper and a small content of up to 2% beryllium, up to 1.2% nickel and cobalt, and the rest other metals. They have a Rockwell C hardness of 35-40 HRc and a tensile strength of about 1250 N/mm2.
For its part, AlBr tools are manufactured with 77% copper and a content of up to 12% aluminium, up to 6% nickel, up to 5.8% iron and manganese, and the rest of other metals. They are less hard and resistant than the previous ones, with a Rockwell C hardness of 25-30 HRc and a tensile strength of approximately 800 N/mm2.
However, most of these metals are softer than the steel that makes up common tools. This means that non-sparking tools wear out more quickly, and since they come with no warranty against warping or breakage, they require frequent maintenance, as we’ll see later.
Other Properties of Non-Sparking Tools
In addition to the spark-reducing properties imparted by their materials, non-sparking tools often have other features as well.
For example, many manufacturers give their non-sparking tools anti-magnetic properties. This means that these tools can be used in environments that include equipment sensitive to magnetism, such as devices for scanning, demining, disarming, etc.
Others incorporate anti-corrosion properties into their non-sparking tools. In a flammable environment, corrosion and oxidation can be extremely dangerous, as impacts on the rust can initiate a thermal reaction capable of igniting an explosive atmosphere. Non-sparking tools with anti-corrosion properties are special for work in marine or underwater environments, for example.
What non-sparking hand tool can we buy?
Manufacturers offer a wide variety of these tools that allow a multiplicity of applications: hammers, socket wrenches, combination wrenches, Allen keys, torque wrenches, adjustable wrenches, parrot beak pliers, Stillson wrenches, pliers, picks, screwdrivers, chisels, axes , files, spatulas, shovels, pipe or tube cutters, saws and hacksaws, graduated rules, bench vices, wire brushes, wedges, scissors, knives, punches, rakes and many more. A curious case that we have already commented on is that of the anti-spark photo camera, or better said, adapted for explosive environments.
Kits containing non-sparking tool kits are also available. These sets may comprise different tools (for example, a 4-piece set that includes a screwdriver, pliers, open-end wrench, and hammer) or the same tool in various sizes (for example, a 14-piece set that includes socket wrenches) .
How to use and care for non-sparking tools?
Since they are more brittle than their common counterparts, it is clear that proper use and maintenance will enable long life for non-sparking tools. Let’s see how we should proceed whenever we need them and review some recommendations from the Occupational Safety and Health Administration (OSHA, United States) to work in a safe environment.
- Keep tools clean and free of ferrous or other contaminants that may affect their non-sparking properties.
- Do not use non-sparking tools in direct contact with acetylene, due to the possible formation of explosive acetylides, especially in the presence of moisture.
- During normal use, hammers and chisels will progressively show some damage to the striking faces of the hammers, or to the cutting edge and striking end of the chisels. When this occurs, the tools must be repaired immediately to prevent eye injuries due to shavings being dislodged from the material during use.
- Do not store hammers and other tools with wooden handles in places where the wood can dry out and contract, as this will increase the risk of the handle breaking and the head coming loose.
- Avoid excessive impacts that can damage the handle of hammers and axes. Fiberglass handles may offer advantages over wood handles in terms of breaking strength and tolerance to harsh environmental conditions. Fiberglass handles fail progressively rather than suddenly, reducing the risk of injury or damage.
- When selecting a wrench, the jaw opening should fit snugly and tightly over the head of the nut or bolt it is being applied to. This especially applies to non-sparking tools, as they do not have the hardness of steel tools.
- Keep in mind that there are no 100% non-sparking tools. In any workplace where there are open flames or sparks, make sure that an explosive atmosphere is not formed, such as flammable vapor-air mixtures and organic dust mists such as flour or coal.
- Accepted safety and maintenance standards for common steel hand tools should also apply to non-sparking hand tools, in addition to recommendations specific to the alloys used.
- When sharpening non-sparking tools, follow normal safety procedures, such as eye and face protection, and use of local exhaust or ventilation systems to remove hazardous materials, dusts, and vapors from the workplace.
- Use a gas detector to monitor the Lower Explosive Limit (LEL) of a workplace and when it is exceeded, stop activities and evacuate immediately.
In a future article we will go a little further and consider the criteria to consider in choosing the right alloy non-sparking tool based on the application and intended use.