By using a vapor quenching method, Fe//xTi//1//0//0// minus //x alloys have been made over a wide composition range. A sharply defined boundary separates the amorphous alloys (30 less than equivalent to x less than equivalent to 80) and the metastable crystalline bcc alloys (82 less than equivalent to x less than equivalent to 100). Across the boundary, changes in properties occur as a result of structural differences. The temperature coefficient of the resistance changes sign and magnitude. From crystalline to amorphous, the magnetic ordering temperature decreases by over 600 K accompanied by a reduction in the magnetic moment by 1/3. In contrast, there is no discontinuity associated with structural changes in Co-Ti alloys.