Quick answer: bar stock describes a supplied shape used as machining feedstock; forged describes a manufacturing route. They are not opposites. Bar stock can be rolled, cold-finished or forged, and a forging can be supplied as a rough blank or near-net-shaped component.
“Bar stock” normally identifies round, square, hexagonal or flat material ordered by section and length. “Forging” identifies material shaped by compressive deformation. A purchase order that says only “forged bar stock” is incomplete unless it also defines grade, specification, condition, dimensions, machining allowance and acceptance tests.
The finished part can be machined economically from a standard section, the bar specification provides the required properties, and material waste is acceptable. Shafts, pins, fasteners, valve stems and general turned parts are often evaluated this way.
The component is very large, has a shape that makes bar machining inefficient, requires a forging-specific code qualification, or needs defined test locations and NDT acceptance for critical service. The benefit must be demonstrated by specification and inspection, not assumed from the word “forged.”
Standard bar often has lower tooling and procurement cost and is easier to replace in repeat production. A near-net forging can reduce machining chips and machining time for bulky geometry, but may require longer planning, heat treatment, sampling and additional examination.
Neither route guarantees cleanliness, strength or fatigue life. Confirm melting practice, heat treatment, section size, mechanical tests, surface condition and ultrasonic acceptance where relevant.
For standard feedstock, review stainless steel bar options. For critical parts, send the drawing so the most practical route can be assessed.