Contact probes with continuous plunger (e.g. KF11, KF16, KF18, KF33...) are used for applications with guiding plate. The stepped plunger (e.g. KF12, KF17, KF04, KF15...) could still be centered by the bore when approaching, but could catch on the guiding plate with the step when moving away and be pulled out of the mounting receptacle.
In high-current applications, ideally no voltage should be applied or no current should flow during the contacting process or when releasing the contacting. Otherwise, a spark can occur which damages the contact surface. To minimize or prevent such contact burn-off, FEINMETALL offers heads made of a special silver alloy. This minimizes contact burn-off, reduces contact resistance and increases probe life. The soft silver also adapts to the DUT contour, allowing better contact or higher currents to be implemented.