Areas that should not be soldered may be covered with solder resist (solder mask). Layers of intermetallics can form between the solder and the soldered material. Fillets commonly appear on welded, soldered, or brazed joints. Leads may be soldered either manually or by a wave soldering machine. The parts can then be soldered or brazed conventionally. Small mechanical parts are often soldered or brazed as well. Crimped connections are common alternatives to soldered connections. Brass bodies are often soldered together, while keywork and braces are most often brazed. Sheet-metal fins can be soldered onto a rectangular copper body. Copper is readily soldered to make durable connections when necessary. The leads can be easily soldered on to the connector from an original battery. Alternatively, the other side may be soldered to a motherboard or daughtercard. The 700 and 701SDX have RAM soldered to the motherboard. Titanium cannot be soldered without first pre-plating it in a metal that is solderable. Compression fittings are not as robust as soldered fittings.