In our continuing series focusing on essential tools, here we look at hammers. There is a bewildering array of hammers out there and choosing the right one for the job is vital to get the best finish possible and to avoid damage, both to your piece and to your other tools.
Different hammers are used with sheet metal to bend and shape it to create the desired finished effect. As you are using your hammers to strike your piece it is important that the heads are kept clean and highly polished as any defect in the surface of the hammer will be transferred to your piece with each strike. Similarly, any surface your piece is placed on whilst hammering that has any damage to the surface will be transferred to the back of your piece as you strike it. Hammering in particular demonstrates the need to show your tools as much care and respect as you do your pieces.
It is important to remember that hammering will cause your piece to become work hardened so frequent annealing is essential, as work hardened sheet will become brittle and may crack or even break.
Here we offer you a guide to the hammers you might expect to find in a silversmith’s kit and explain their individual uses.
A household hammer or jobing hammer is the first hammer you will need. Every other hammer that you use will come into contact with the surface of your finished piece and as such needs to be kept clean and highly polished and used only for its intended purpose. However, you will also need to hit other tools with a hammer as you work on your piece, for example doming tools or a centre punch are hit with a hammer to imprint the surface of the metal. If you use your jewellery hammers for this purpose you will damage them and this will in turn cause damage to your piece. Having a household hammer in your tool kit enables you to hit other steel tools without having to be concerned that the surface of your hammer may become damaged.
As the name implies, a rawhide hammer is typically made of rawhide with a wooden handle. It will usually have a cylindrical head. This hammer won’t mark your metal and is typically used to work harden your piece or to flatten it though it can also be used for planishing.
This hammer is flat or slightly curved and used as part of the finishing process to work out ridges and imperfections from sheet metal, after it has been fashioned into its desired shape using other stretching techniques. Hitting the metal too hard will causing dimpling so a series of softer blows will achieve a more desirable finish. Other hammers can be used for this task, typically a rawhide hammer but this hammer will be less effective on significant imperfections.
A raising hammer is typically used to form sheet metal into the desired shape using a series of passes over the metal where the hammer is used to strike the sheet in a particular direction causing it to change shape. It is usually done in conjunction with a stake which helps to form the metal into the desired shape. Care should be taken as raising will cause the sheet to become thinner the more it is struck and frequent annealing will be required.
Texturing is the process by which patterns are made in the surface of metal. There are a variety of hammers available that can be used to texture your metal from hammers that are specifically designed for that purpose with designs in the head that will imprint on the metal as it is struck, to hammers that perform other specific functions which can also be used to create a pattern in the metal’s surface. A household hammer can also be used to create a texture but take care if its surface has any marks or damage not to unintentionally damage your piece.
A rivet hammer has one end that is flat and can be used for general purpose and one that is chisel shaped specifically for spreading rivets.
This hammer is used on the reverse surface of the metal to create a pattern by hammering a design that will be raised on the finished side. Chasing is the opposite technique and is used on the finished side to refine the design by sinking the metal from the front.