Hex and Torx keys are made from a number of different varieties of steel. The steel is alloyed with a small percentage of other material elements to give it the required properties of strength, hardness and ductility (see Hexagon and Torx key glossary of terms) for use as a hex key.Some of the more common steel types used in the production of Torx and hex keys are chrome vanadium, S2, 8650, high tensile and stainless steel.
Why is steel used to make hex and Torx keys?
Steel is used as, of all the materials that have the required physical properties of strength, hardness, and ductility for use as a Torx or hex key, it is the cheapest and easiest to manufacture.
What is an alloy?
An alloy is a metal that has been made by combining two or more metals to produce a final product which has better properties than the pure elements from which it is made.
Alloy steel is made using more than 50% steel in combination with other elements, although the steel content of alloy steel is normally between 90 and 99%.
Chrome Vanadium
Chrome vanadium is a type of spring steel that was pioneered by Henry Ford for use in the Model T car in 1908. It contains approximately 0.8% chromium and 0.1-0.2% vanadium, which improves the strength and toughness of the material when it is heat treated.
One of the things that makes chrome vanadium particularly suited for use as a Torx and hex key material is its excellent resistance to wear and fatigue. Chrome vanadium is now most often seen in tools sold in the European market.
8650 steel
8650 is very similar to chrome vanadium in its properties, although it contains a lower percentage of chromium. It is the most common type of steel used in Torx and hex keys in the U.S. and far east markets.
S2 steel
S2 steel is harder than chrome vanadium or 8650 steel, but it is also less ductile and, as such, more prone to shattering. It is more expensive to produce than 8650 steel or chrome vanadium and this, along with its lower ductility, means it is only used by a few manufacturers.
High tensile steel
High tensile steel has several alloying elements added to its composition that help improve its strength, toughness and wear resistance. These alloying elements include silicon, manganese, nickel, chromium and molybdenum.
Stainless steel
Stainless steel is a steel alloy which contains at least 10.5% chromium. The chromium helps prevent the steel from rusting by forming a protective layer of chromium oxide when exposed to moisture and oxygen. This protective layer prevents a build-up of rust forming on the steel.
Stainless steel Torx and hex keys are used for driving in stainless steel screws. This is because using other Torx or hex keys made of ferrous metals with stainless steel screws leaves microscopic traces of carbon steel on the fastener head, which can result in rust stains or pitting corrosion appearing over time.
CVM
CVM stands for chrome vanadium molybdenum, and is meant to give similar properties to chrome vanadium but with reduced brittleness due to the addition of molybdenum.
Manufacturer-specific steels
Many manufacturers will develop their own specific grades of steel for use in tools. There are several reasons why a manufacturer may wish to do this.Developing a grade of steel for a specific type of tool can allow a manufacturer to tailor the properties of the steel for the purpose of the tool it’s to be used in. Areas that a manufacturer may want to improve are wear resistance for increased tool life or ductility to prevent shattering.
This can help improve the tool in certain key areas, giving it an advantage over the tools of competitors. As a result, manufacturer-specific steels are often used as a marketing aid to convey the impression that a tool is made of a superior material.
It may also be possible for a manufacturer to develop a steel that maintains the characteristics and properties of other steels but costs less to produce. For these reasons, the exact make up of manufacturer-specific steels is a closely guarded secret.Some examples of commonly found manufacturer-specific steels include HPQ (high performance quality) steel, CRM-72 and Protanium.
CRM-72
CRM-72 is a special high-performance grade of tool steel. It is mainly used to produce Torx keys, hex keys, socket bits and screwdrivers.
Protanium
Protanium is a type of steel developed specifically for use in hex and Torx tools and sockets. It is claimed to be the hardest and most ductile steel used for such tools. Protanium has very good wear resistance when compared to other steels.
What type of steel is best?
With the exception of stainless steel that is clearly the best for use with stainless steel fasteners, it’s impossible to say with any degree of certainty which steel is best for a Torx or hex key. This is due to the slight variations that can be applied to each type of steel and manufacturer’s closely guarding the exact make-up of the steel they use, preventing direct comparisons from being made.
Handle materials
T-handle materials
There are generally three materials used to make the handles of T-handle hex and Torx keys: vinyl, TPR, and thermoplastic
Vinyl
Vinyl handle material is most commonly seen on continuous loop T-handles or ones without a short arm. The vinyl coating of the handle is applied by dipping the T-handle in plasticised (liquid) vinyl then removing the handle and letting the vinyl set. This results in a thin vinyl layer coating the T-handle.
ADVANTAGES
DISADVANTAGES
Provides better grip and comfort than if handle was not coated with vinyl
Cheaper than other handle materials
Available in many colours
Cannot be ergonomically moulded to fit hand
Can’t be used on T-handles with a short arm
Provides a less cushioned grip than TPR (see below)
Thermoplastic
Thermoplastics are a group of plastics that, when heated above a certain temperature, become soft and malleable. This allows them to be moulded into many shapes, and upon cooling they return to their original solid state.Types of thermoplastic that may be used to make handles for T-handle hex and Torx keys are: nylon, polyethylene, polypropylene and polystyrene.
ADVANTAGES
DISADVANTAGES
Available in many colours
Can be moulded to give a more comfortable shape
Can have a textured finish to aid grip
Provides a less cushioned feel than TPR or vinyl
TPR
TPR stands for thermoplastic rubber. It is a material that combines the properties of thermoplastics with those of rubber. TPR is not rigid enough to be used by itself as a handle material so is often combined with a thermoplastic, such as nylon, to give a softer, more comfortable grip. These handles are often called bi-material or composite handles.
ADVANTAGES
DISADVANTAGES
More comfortable and provides better grip than other handle materials
When combined with thermoplastics can give an ergonomic shape to the handle
More expensive to produce than other handle materials
Folding handle materials
The handles of folding hex and Torx key sets are made of either metal, plastic or a composite.
Metal handles
Metal handles for folding Torx and hex keys can be made of two types of metal: steel or aluminium.
Steel handles
Steel handles are usually found on the cheapest sets of folding Torx and hex keys. Steel can easily be formed into a basic handle shape but more comfortable ergonomic designs are not possible. Steel handles have to be galvanised (see Hexagon and Torx key glossary of terms) to protect them from corrosion.
ADVANTAGES
DISADVANTAGES
Cheap to make
Stronger than aluminium
Colour variations are not possible
Less comfortable than other handle materials
Aluminium handles
Unlike steel, aluminium does not rust so does not require galvanising. Aluminium folding hex and Torx key handles may be anodised (see Hexagon and Torx key glossary of terms), though. This is normally done to give a bright colourful finish that can be used to make the tool stand out at a worksite or to distinguish between metric and imperial sets. Aluminium can be formed into many shapes though it is still not possible to make ergonomically shaped handles from aluminium that will be as comfortable to use as those made of plastic.
ADVANTAGES
DISADVANTAGES
Lighter than steel
Can be anodised in many different colours
Does not rust
Not as strong as steel handles
Can not be formed into shapes that are as ergonomic as plastic handles
Plastic handles
Plastic handles are made from a type of thermoplastic. Thermoplastics are a group of plastics that, when heated above a certain temperature, become soft and malleable. This allows them to be moulded into many shapes to give a more comfortable grip than metal handles. Upon cooling, the plastic returns to the original solid state.Types of thermoplastic that may be used to make handles for folding hex and Torx keys are nylon, polyethylene, polypropylene and polystyrene.
Better-quality plastic handles will sometimes be referred to as being bi-material. This means they are made of two types of plastic. The first type will be a thermoplastic such as nylon, that is used for the main body of the handle, and the second will be a TPR (thermoplastic rubber). This TPR gives the handle a softer, more comfortable feel whilst improving the grip.
ADVANTAGES
DISADVANTAGES
More comfortable and ergonomic than metal handles
Lighter than metal handles
Do not rust
Large variety of colours available
More expensive than steel handles
Not as strong as some composite and metal handles
Composite handles
A composite is a material made of two or more substances or materials with differing properties that, when combined, produce a material with overall properties more desirable than those of the original individual substances, or materials. A common example of a composite is fibreglass.
This term can be a bit confusing when used to describe the handles of folding Torx and hex keys as different manufacturers can use it to mean different things. Some refer to bi-material plastic handles as being composites, while others may use the term composite to mean the plastic handle is reinforced with steel to give it added strength. Some will describe handles made of fibreglass or GRP (glass reinforced plastic) as being composite handles.
One company claims it has developed its own composite material for use in the handles of its folding Torx and hex keys, that is actually up to 40% stronger than steel.
ADVANTAGES
DISADVANTAGES
More comfortable and ergonomic than metal handles
Lighter than metal handles
Do not rust
Large variety of colours available
Stronger than other handles
Most expensive type of handle
What is the best type of handle for Torx or hex keys?
A reinforced or composite handle will provide plenty of strength, allowing you to apply high torque loads. These types of handle are also available in bright colours, meaning you are less likely to lose them or leave them behind at a job. Some have soft TPR sections, giving better grip and making them more comfortable to use.
