Monday, May 25, 2015

Hammer Facts

Hammers come in many shapes and sizes for jewellery making. There are many specialised hammers, too many to mention. The big question is which to use when?  How many does one need to buy in order to successfully do cold connections or other jewellery techniques?  Those are very loaded questions indeed.

Some basic understanding of use, shape and result is useful to know what hammer needed for the job required.  One important thing to keep in mind, do not use highly polished, mirror finish hammer faces to strike punches or stamps as this will mar the surface of the hammer.  Then when using the same hammer face later on, that mark will transfer to metal being struck.  Use the hammers for their appropriate use!

Rivet Hammer
This hammer has typically a flat face and a pointed wedge face.  A rivet hammer can be petite at less than 3 ounces/75 grams or significantly larger at over 1 pound/500 grams.  The wedge face is used to first start the rivet flare.  As this face is long and thin, it can also be used to put in long line texture into sheet metal or thick wire.  

The flat face is often very flat without any concave curve and is used to finish the rivet flare process.  If metal is struck with the flat face at a diagonal, the sharp edge will leave a long line mark in the metal surface.  Do not use this hammer to strike stamps or punches.

Ball Pein (Peen) Hammer
A budget hammer with many uses.  One face is completely flat like a nail hitting hammer and can be used to start the rivet flaring process.  If metal is struck with the flat face at a diagonal, a curved line will divot in the metal surface.  The other face is a half circle useful for creating tube rivets, divots, bumps and hammered texture in metal work.  If this is a cheap hammer and the flat face surface is not important, you can use this hammer face to strike punches and stamps. 

Ball Pein hammers are so useful because they are readily available at any hardware shop, cheap and the flat face can be marked easily with metal files to become specialised texture hammers for metal design.

 Chasing or Repousse Hammer
This hammer has a characteristic very wide flat or slightly concave curved face and a half circle face.  The flat face can be used to flatten curved metal, smooth out rough edged texture in metal and riveting. The wide concave face means that the hammer will strike flat and leave smooth edges.  It is harder to hit this face on a diagonal to leave a hammer face side mark in the metal.

The half circle face is the same as on a ball pein/peen hammer.  This face has a tight convex curve and will leave very small, deeper divots in metal surface.  Used for creating tube rivets, divots, bumps and hammered texture in metal work.  Do not use this hammer to strike punches or stamps.

 Repousse Wedge Hammer
Just an example of how specialised hammer heads can get.  This would be used to introduce curves into sheet metal like into a bangle shape or create 3D relief pictures in sheet metal.  Do not use this kind of hammer to strike punches or stamps!!! 

Brass Dead Hit Hammer
Finally, the hammer with the sole purpose of striking stamps, disc cutting, coming and punches!  This hammer is heavy, often over 1 pound/500 grams.    The head is soft brass which will take the damage first, saving expensive cutting, punching, stamping or curving tools from damage.

How Hammers Move Metal

Each hammer face interacts with metal differently pushing metal aside at the point of impact. Many hammers will easily mark soft steel blocks too, so take care to aim and pay attention to the angle the hammer face is held when striking.

 Shallow Concave Face and Flat Curveless Faces
Concave Face Metal Movement
The shallowly domed wide flat face of a hammer will push metal out in every direction leaving a shallow divot and gentle shaping.

If held at a severe diagonal, the rounded edge of this hammer will leave a half moon mark in the surface of the metal.

A completely flat hammer face will also move the metal in the same direction as the diagram at right.  The only difference is that any metal surface that extends beyond the hammer face will also have the sharp edge straight line marks too.

Deep Concave Face
A deep semi circular concave face like the Ball pein hammer is so much fun to play with!  This face also pushes out metal in all directions from point of impact but  leaves a much deeper, smaller circular divot in metal.  It works well to spread tube rivets open since the curve gently pushes the tube open.  This face is perfect for texturing metal surfaces, just have patience to strike the surface a LOT for a truly even pattern.

Wedge Face
Way the Wedge spreads Metal

The long wedge curved edge has a side profile of a U shape rather than the complete circle of a concave face. The face is completely curved but the edges can sometimes be left sharp on more budget tools.
This face will cause the metal to move perpendicular to the face of the wedge and leave a long line divot.  The line divot will be deeper if struck with greater force.  Great for giving unusual textures to sheet metal or gauge wire components.

This shape can help introduce a gentle bend in wire if held at an angle while striking the wire.  Just take care not to leave divots in your anvil or dapping block too!

Etching with a Hammer

It was mentioned that budget hammers with flat faces are excellent for tweaking.  If you like the look of etching or some complex regular textures, these can be carved into the flat face of a cheap hammer with grinding sand belts, dremel cutting discs, drills and metal files.   The sharp edges of a flat face can be sanded back into a gentle curve so the texture is the only thing making contact with the metal surface.

Martha Aleo of Ornamento Blog gives a great visual for this concept and using other tools to texture along with some other handy DIY tips.

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