1.4501 is the Werkstoff number for the super duplex stainless steel most commonly known as Zeron 100®, or UNS S32760. Werkstoff numbers were developed by the German standards body DIN; the word translates roughly as "material".
Zeron 100 was the second super duplex stainless steel brought to market, several years after we developed the original Ferralium® 255. It was developed by Mather & Platt, a UK-based pump manufacturer, and the Zeron 100 trademark is now held by Rolled Alloys Inc.
The alloy is more widely referred to as Alloy 32760 (UNS S32760, 1.4501, F55). It uses the 25% chromium content common to other super duplex stainless steels, plus a deliberate tungsten addition claimed to selectively improve corrosion resistance.
We stock Alloy 32760 from 1/2" to 16" diameter in solid bars, plus plate up to 2 1/2" thickness.