Fittings made with a particularly high level of attention in manufacture and inspection. To heat metal in order to lower its hardness. The term anneal refers to the heat treatment given all 300 series stainless and most 400 series stainless by the steel mill after the raw material has been completed but before fittings are manufactured. For example, fittings of 410 stainless may score over 200,000 psi after manufacture and be too brittle. Stretching a fitting to the point that it breaks.
Elongation decreases as strength and hardness increase.
An accelerated degree of corrosion occurring when two different metals are in contact with moisture, particularly seawater. All metals have what is termed a specific electric potential, so that low-level electric current flows from one metal to another. The further apart the metals on the chart, the more electric current will flow and the more corrosion will occur. No serious galvanic action will occur by combining the same metals only dissimilar ones. The metals listed at the top of the table below will corrode first due to galvanic reaction before those at bottom of the table.