How to Properly Use Auto Body Hammers

hands hammering car metal with auto body hammer

Auto body hammers and dollies are an essential part of any auto tool kit and come in handy when doing metal sheet work. These hammers may look simple but require a high level of skill to be used correctly.

You may find it easy to drive nails into a wall or wood with your regular hammer, but the lumpy metal you'll use auto body hammers and dollies on is different. An auto body hammer makes it possible to deliver accurate blows to sheet metal.

To use them properly, you must understand the various types of auto body hammers.

Types of Body Hammers and Dollies

Auto body hammers are named after the shape of the head opposite the face. These include chisel, cross peen, pick, and claw.

The pick hammer is used to raise low spots in metal finishing, while a cross peen or cross chisel is used to repair a damaged crevice or ridge.

The face of an auto body hammer is usually round or oval-shaped with a curvature of approximately 1¼ inches to two inches. The curvature plays an important part in thinning and stretching the metal sheet.

Lightweight auto body hammers of about 12 ounces are ideal for delicate work, while hammers weighing 18 ounces or more are best suited for heavy collision repair. If you are looking for something durable, hammers with fiberglass handles are an ideal choice and will work much better than hammers with wooden handles.

Dollies also come in various shapes, and the one you need depends on the nature of the work you are performing. For heavier sheet metal, it's possible to use a heavier dolly.

hands flattening car metal with auto body hammers

Hammer on Dolly Technique

Place the dolly precisely behind the affected area. With an auto body hammer, lightly tap the metal that is placed on the dolly.

Make sure to tap lightly so the metal does not stretch beyond its limit. After a few taps, check to see if the dent still persists by running your hand over the area. If the dent is still there, lightly pound the metal again until the dent disappears.

While hammering, make sure you press up on the dolly with sufficient force. If you fail to apply adequate pressure, you may end up denting the sheet metal instead of smoothing it as the area being hammered moves up while the surrounding metal stays where it was.

hands flattening car metal with auto body hammers

Hammer Off-Dolly Technique

You should master the hammer-on-dolly technique before trying this technique. In the hammer off-dolly technique, the metal needs to be placed a ½ inch away from the dolly.

The metal will be pushed in the opposite direction of the hammer. The dolly touches low spots on the metal as you continue to hammer on the high spots. This makes the high spots go down while the low spots move up with every rebounding action of the dolly. Make sure to keep close contact between the hammer and dolly for better rebound action.

A good idea is to practice with a sheet of junk metal in order to master both techniques. Starting with simple tools and then moving on to more powerful tools will help you master these techniques more quickly.