The machine shop finished making us nice cylinders, to which we applied all those strain gauges and wires. Check out that pretty copper-colored patina on the outside. That comes from a successful heat treatment, which locks in the desired hardness. Our old ones didn't have this patina, which may be one indication of why they crapped out on us. We also had the shop make us some hemispherical seats for the load cells. The piece attached directly to the piston has a convex surface and the large visible partner piece has a concave surface. That way, when you apply the load any small deviations in alignment are worked out. Above is a our vertical load cell and below is the horizontal, which applies the normal stress.