858 Rugged Spring-Loaded Connectors Mill-Max 858 Rugged Spring-Loaded Connectors are available in 2- to 6-position connector variants with a precision-machined piston/base (modular contacts for use on a 4mm grid). These connectors are available in 858-22-00x-10-0x and 858-22-00X-30-0x. The 858-22-00x-10-0x connectors are designed for manual placement into ø0.048±0.003' plated through-holes in the circuit board before soldering, 858-22-00x-30-0x connectors are designed for manual placement onto ø0.100' solder pads. These Pistons offer 0.045' mid-stroke and 0.090' maximum stroke. The 810 SMT connector's gold-plated components offer a 1,000,000 minimum lifecycle. These connectors also include high-temperature thermoplastic insulators suitable for wave and reflow processes.