Iso 8015 Jun 2026

Actually, the old default was the "Envelope Requirement" (Taylor Principle). ISO 8015 did something radical: It said that . That is, each specification on a drawing stands alone . A size tolerance does NOT control form unless explicitly stated. A flatness tolerance does NOT control parallelism unless explicitly stated.

If a drawing is created in Europe using ISO standards but inspected in a facility accustomed to ASME standards, the inspector might assume the Envelope Principle applies. They might reject parts that are actually within spec according to ISO 8015, or vice versa. iso 8015

In the world of precision engineering, silence is not golden. For most of the 20th century, a silent assumption ruled every workshop, every drawing board, and every inspection lab on the planet. That assumption was called the Principle of Independency —or more commonly, the "chain of defaults." If a drawing didn’t specify a tolerance, a machinist could assume one. If it didn’t mention a datum, the part’s natural edges would do. This unspoken language worked, but it was brittle, ambiguous, and often led to costly fights over who was "right." Actually, the old default was the "Envelope Requirement"

Chaos. Shipping stopped. A $2 million order was held hostage by a missing "⌖" symbol on a drawing. A size tolerance does NOT control form unless

But inside, it detonated the old world.