When a cast breaker part failed, we machined a stronger one.

The challenge

The part shown is from the operating mechanism of a Siemens SF6 circuit breaker. The original is an OEM aluminum casting — and during operation it failed catastrophically, fracturing clean through the splined hub. When a cast mechanism part lets go like this, the breaker is out of service, and a like-for-like replacement often isn’t sitting on anyone’s shelf.

Our approach

With the OEM casting in pieces, we reverse-engineered the component directly from the failed part — capturing the spline, bore, and lever geometry — and machined a replacement from solid billet stock instead of casting it. A machined billet part is more homogeneous than a casting, without the porosity and weak grain boundaries that can drive this kind of fracture, so the replacement is built to outlast the original.

The result — a full turnkey repair

Because Southern Switch & Contacts runs both a machine shop and a substation field crew, we didn’t just ship a part. Our team installed the new component on-site and returned the breaker to service — one vendor, one point of accountability, from the broken casting to power back on. That is the difference between ordering from a parts catalog and working with a machine shop that can make what failed and put it back in service.