How are pick axes manufactured?
How are pick axes manufactured? |
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Heat treatment |
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Heat treating and tempering are manufacturing processes used to alter the physical properties of metal and other materials. Heat treating involves heating the metal up to a very high temperature and then quenching (rapidly cooling) it; this increases the hardness of the metal but will also make it more brittle. | |||
Tempering |
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Tempering is performed after heat treating and also involves heating the metal but to a lower temperature than heat treating, then letting it cool slowly. Tempering will decrease the hardness and brittleness of the metal and at the same time increase its toughness.
By controlling the temperature the metal is heated to during tempering it’s possible to alter the final balance between the hardness and toughness of the metal. |
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Forging |
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Forging is a manufacturing process that makes the finished product stronger than a cast or machined part, by altering the direction of crystals within the metal. Forging compresses the metal into the desired shape.
This can be achieved by either drop forging using a hammer and mould (die) or roll forging passing the metal through two or more rotating rollers. |
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Drop forging |
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Drop forging uses a hammer (ram) that is raised up and then “dropped” onto a metal workpiece compressing its shape into that of a mould (die). This process makes the metal workpiece stronger by altering the direction of the crystals in the metal structure. | |||
Roll forging |
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Roll forging involves passing the metal workpiece through a series of shaped rollers until the desired final shape is achieved. This process can align the crystal structure of the metal in one direction making in stronger in that direction.
Because of this, roll forged pick axe heads will be stronger than drop forged or cast heads. |
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What is an alloy? |
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An alloy is a metal that has been made by combining two or more metals together to produce a final product which has better properties than the pure elements from which it is made. Bronze is an example of an alloy.
Alloy steel is an alloy that is made using more than 50% steel in combination with other elements, although the steel content of alloy steel is normally between 90-99%. |
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Powder coating |
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Powder coating is a kind of finish usually found on metals that, instead of the usual liquid paint, uses a dry powder that is cured under heat. A much tougher finish can be achieved with powder coating than conventional painting methods.
Powder coating is used on some pick axe heads to help protect them from corrosion. |
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Which should you choose? |
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Selecting a pick axe head that has been heat treated and tempered will give it more strength and toughness. Roll forged pick axe heads will be stronger than drop forged. However, roll forged heads are likely to cost more than drop forged, which may be a consideration if you only plan on using your pick axe for a small amount of work.
Powder coated pick axe heads will be less likely to rust and so should require less maintenance. |
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