Today we want to bring you another fascinating topic from our daily work. This article gives you all the important facts about cold work steel: we cover its composition, its uses and the difference from hot work steel.
Cold work steel is encountered in many places in everyday life, and we use it as a matter of course. Whether it is a suitable material is determined by the properties of cold work steel, which certainly have their peculiarities.
As the name suggests, cold work steel is a material not suited to use at high temperatures. In general, a temperature ceiling of 200° Celsius applies if you want to use this material. Hot work steel, by contrast, can be used at surface temperatures of up to 400° Celsius.
Important properties: cold work steel explained
The outstanding properties of cold work steel are hardness, toughness and wear resistance. That is why the material is popular for demanding tool applications in industry and trade. However, there are essential differences between alloyed and unalloyed cold work steel - hence a brief digression at this point:
Unalloyed cold work steel
This steel is characterised by a soft core, which forms even though it is cooled quickly in a water bath for hardening. The cause is the carbon content, which lies between 0.45 and 1.50%. It means that unalloyed cold work steel no longer hardens fully through even at relatively low material thicknesses.
Alloyed cold work steel
This material is obtained by tuning the individual components of the composition to one another. The right mixture of manganese, silicon, molybdenum, chromium, nickel, tungsten and vanadium produces a work steel with high overall strength. Depending on the alloy, alloyed cold work steel impresses with high hardness or toughness. These two material properties run counter to each other, so higher toughness inevitably leads to lower hardness - which is also why there are numerous different alloys of cold work steel.
Cold work steel vs. hot work steel
At this point we want to return to how hot work steel and cold work steel differ, to help you make the right choice of material. First, of course, there is the different composition, which accounts for the different properties.
The different temperature tolerances of cold work steel and hot work steel mean they are suited to different tools. Driving in a nail with a hammer produces a far lower surface temperature than sawing or drilling stainless steel. Because temperatures above 400° Celsius can occur there, there is a further type of tool steel: so-called high-speed steel, which can be used up to a temperature of 600° Celsius.
Common uses of cold work steel
Here too, we must distinguish between alloyed and unalloyed. Unalloyed cold work steel is used for hand tools and deep-drawing tools. Pliers are almost always made of cold work steel - at least when they are only to be used in the temperature range up to 200° Celsius. Thanks to its soft core, unalloyed cold work steel is also very well suited to striking tools such as hammers.
Alloyed cold work steel is very popular in mould making and in the food industry. Furthermore, tools for cutting and forming are often made from this material.
How you can work cold work steel
Cold work steel can be worked in many ways. You can drill it without difficulty so that you can fasten it. It is also well suited to welding and soldering, giving you various options for assembly.
However, there are a few metalworking processes for which cold work steel is not so well suited: polishing, spark erosion, etching and hard chrome plating. You absolutely must bear this in mind when choosing your material - if these processing methods are important for your project, you must use hot work steel instead.
Hardening cold work steel
As you have already read, hardness is one of the special material properties of cold work steel. So let us explain how cold work steel can be hardened. First, the workpiece must be brought to a temperature of 780 to 840° Celsius and held there for at least 15 and at most 30 minutes. The heated workpiece must then be quenched in water or oil to achieve rapid cooling.
Tempering
The workpiece must then be brought to the correct tempering temperature and held there in a furnace. As a rule of thumb, one hour in the furnace is needed per 20 mm of material thickness.
Soft annealing
For soft annealing, your cold work steel workpiece must be brought to a temperature between 710 and 740° Celsius. Over a period of 2 to 5 hours, the furnace temperature must then be reduced slowly by 10 to 20° Celsius per hour. Once a temperature of 600° Celsius is reached, further cooling takes place in room air.
Do you need cold work steel workpieces for your project?
Now that you know what cold work steel is, you can surely decide whether it is the right material for you. Unfortunately, we have to tell you that it is not a product from the standard range of DIY stores. With luck, you may be able to order sheets there in the required thickness - but you will probably then have to bring them to the right dimensions at home yourself. It should be said that cutting sheet metal is far more difficult than cutting wood.
To avoid mistakes when cutting, you can of course also turn to a professional. Besides local metal fabricators, that includes us at ESC Burg. With us, you can order individual sheets in various steel grades by telephone - professional advice always included. Our experienced staff advise you without obligation and free of charge on the phone.
We deliver made-to-measure products
We have automated our production as far as possible and trained our employees well. That is why we can meet our target production time of 48 hours from receipt of order for almost every purchase.
So you only have to wait a few days until you hold a sheet of cold work steel or heat-resistant steel made to your specifications in your hands. And we work not only fast but also precisely: your order is executed with millimetre accuracy. It makes no difference to us whether you want to build a model with it or need large plates for vehicle construction - our own quality standards ensure that we allow ourselves no deviation from the customer's order.
+49 3921 72-0