Cast-iron

His alibi seemed cast-iron.

Ironbridge in Shropshire takes its name from the world's first cast-iron bridge, which was built there across the River Severn.

To a clay pot, a cast-iron kettle is a dangerous neighbor.

There are still at least a dozen of what once numbered 55 or more of these large timepieces, weighing up to two tons, perched on cast-iron pedestals or columns on important downtown streets.

The cast-iron columns have not withstood the high temperatures generated by fire.

The only part of the passenger railway still in private hands is the rolling stock. The rolling stock companies (ROSCOs) have a cast-iron guarantee that come hell or high water, they still get their charges. Even if half the fleet is parked up in sidings, they are still entitled to all their payments.