An electrodeposition formula and operating conditions were developed and optimized for the high saturation magnetization Co80Ni10Fe10 alloy. The effects of magnetic field application during deposition and in subsequent process operations was investigated. The bulk film magnetic performance was compared to conventional Permalloy. Identical write heads, designed for a 300 Mbit/in.2 operating point, were fabricated and tested for a direct comparison of conventional NiFe and CoNiFe. The yoke thickness of the CoNiFe heads was scaled linearly by the difference in saturation moment. Overwrite performance on high coercivity media demonstrated that the CoNiFe heads performance was equivalent to the thicker NiFe heads. Heads fabricated with yokes deposited in an orthogonal switching field, annealed with no applied field, exhibited reduced Hk in the bulk film measurement and reduced saturation write currents. The addition of boron to the alloy reduced coercivity.