Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Cast metal is produced by pouring molten metal into a mold, where it solidifies into shape. This often results in a coarser grain structure and potential imperfections like porosity. Forged metal, on the other hand, is shaped by applying compressive force (e.g., hammering or pressing) to a heated workpiece, leading to a denser, more refined grain structure aligned with the part's contours, which enhances strength and ductility.Distinguishing between them without specialized equipment relies on visual, tactile, and simple mechanical tests. Here's a step-by-step guide:

1.Inspect for Parting Lines or Seams

Examine the surface closely for mold-related marks. Cast metal typically shows thin, sharp, raised seams or "parting lines" where the mold halves met—often running along the length or at joints. These can be faint but uniform. Forged metal may have thicker, indented "flash lines" or "flashing" from the die edges, which are usually ground down, leaving a smoother or slightly recessed trace. No lines at all often points to forging, especially in high-precision parts like cranks.

2.Check Surface Texture and Finish

Run your finger or a tool along the surface. Cast metal often feels rougher, with a sandy or irregular texture due to sand molds or shrinkage during cooling. Forged metal tends to have a smoother, more uniform polish from the working process, though it may show subtle hammer marks or flow lines in hand-forged items. Drop-forged pieces might have a matte, even finish without the pitting common in castings.

3.Perform a File or Scratch Test

Use a metal file on an inconspicuous area. Cast metal files more easily and may leave a powdery residue or reveal subsurface voids (porosity). Forged metal resists filing better due to its denser structure, producing finer shavings and a more even wear pattern. This test highlights the superior work-hardening in forgings.

4.Conduct a Spark Test (for Ferrous Metals like Steel)

Grind a small area with a bench grinder and observe the sparks. Forged steel produces longer, more branched sparks that split and scatter widely, reflecting its refined grain. Cast steel sparks are shorter, straighter, and less explosive, often with fewer forks. This works best on carbon steels; non-ferrous metals (e.g., aluminum) won't spark reliably.

5.Weigh and Tap for Density and Sound

Forged metal is often slightly denser and heavier for the same volume due to compressed grains. Tap the piece with a hammer: Cast metal gives a duller, more "thuddy" ring from internal inconsistencies, while forged metal resonates with a clearer, higher-pitched tone like a solid bell.