As I see it, there are two aspects to chain strength: the tensile
strength of the metal and its resistance to wear. For any given
material, the tensile strength is proportional to the cross
sectional area normal to the applied tension. It doesn’t matter what
the shape of the cross section is, only the area is important: double
the area and the strength is doubled.
The same isn’t true for wear resistance though. Chains wear as the
result of abrasion between the links, and the rate of wear increases
with the pressure per unit area of contact between the links: the
smaller the contact area, the higher the pressure and the greater the
rate of wear. Think about sawing a piece of pipe or tube. Until you
reach the hollow bit the effort is exactly the same as if you were
sawing a solid rod, but when you reach it the saw just zips through.
Its not dissimilar to sawing a wide bar - it is much more difficult
to saw across the wide bit than across the narrow bit. Incidentally,
this is the reason that chains made of hollow wire wear out very
For maximum resistance to wear then, you need to make the area of
contact between the links as large as possible, and the type of chain
that does this is known as Venetian Box chain. The links are made of
flat strips of wire bent into rectangles. All other things being
equal, eg. quality of soldering, box chains are the strongest.
Regards, Gary Wooding