Lost wax casting, also known as investment casting, is a precise method for creating intricate, detailed metal objects, including pipe fittings. It involves creating a wax mold of the desired shape, coating it with a refractory material, melting out the wax, and then pouring molten metal into the resulting cavity. 

This process is highly versatile and can produce complex shapes with high dimensional accuracy. 

Here's A More Detailed Breakdown: 

Wax Pattern: 

A wax model of the pipe fitting is created, often by hand or using computer-aided design (CAD).

Investment: 

The wax model is coated with a refractory material, like sand or ceramic slurry, forming a mold.

Wax Removal: 

The wax is melted out, leaving behind an empty cavity in the mold.

Metal Pouring:

 Molten metal is poured into the cavity, filling the space where the wax was.

Cooling and Removal: The mold is cooled, and the solidified metal part is removed.

Lost wax casting is particularly well-suited for pipe fittings due to its ability to create intricate shapes and complex geometries with high precision. It's used to produce a wide variety of pipe fitting types, including elbows, tees, and couplings, in materials like stainless steel, brass, and other alloys.