Also known as frame straighteners or frame racks, frame machines are large pieces of equipment most often found in garages or shops that specialize in auto body repair. Frame machines are used to repair damage to vehicle frames, which most often occurs when a vehicle has been in a collision of some sort. Rust can also cause frame damage.
The standard sizes for frame machines are 15, 18, 20 and 24 feet (or approximately 4.6, 5.5, 6.1, and 7.3 meters). Some frame machine companies offer various other sizes. Other companies will custom build frame machines to exact specifications, to comply with space or architectural limitations.
Frame machines also come in a variety of designs. Some are specifically designed for unibody frames, or single unit frames, where the body and the frame are one piece. Others are used for body-over frames, where the body is a separate piece — or pieces — secured to the frame. There are also frame machines that can be adapted for use with either body style. Rectangular frame machine designs are said to utilize space more efficiently than rounded designs.
Portable frame machines, while strong enough to pull misshapen frames back to their proper form, are more compact in size and weigh less than other designs. Because they are easier to move, they have the ability to be used off site rather than only in the garage. Portable frame machines are good choices for shops that also provide wrecker service, as basic repairs can even be done in a parking lot. Portable frame machines are also a good option for racing teams to use at the racetrack.
Some frame machines come complete with frame measuring devices or are designed to add such devices as accessories. Measuring is important for accurate repair, and some of these devices are able to measure several different points of the vehicle at the same time. Saving time is important in auto body repair, both for profit and for customer satisfaction, since most people want their vehicles back as soon as possible. Without accurate measurements, repairs will not be exact, and this will be noticeable in the way the vehicle handles. In some cases, it will also be visually noticeable.
Some other frame machine accessories include special tool sets, tool boards, and parts trays. There are also roof pullers, filing tools, hydraulic kits, chains, and pulling clamps. There are other styles of clamps for securing the vehicle while work is being done as well as many other accessories designed to make auto body work faster, easier, and safer.