NIST’s Million-Pound Weight Stack Restoration is Complete

PML restoration team and leadership in front of the newly refurbished million-pound weightstack. From left to right: Project Leader Rick Seifarth, Sam Ho, Kevin Chesnutwood, and Mass and Force Group Leader Zeina Kubarych.

It’s official: NIST’s 4.45-million newton (equivalent to one million pounds-force) deadweight machine – the largest in the world – is back in one piece after a colossal 16-month effort to overhaul the system for the first time in 50 years.

The year-and-a-half-long saga involved dismantling, cleaning, restoring, and recalibrating about half of the stainless steel discs in the three-story stack of weights.