Fit for purpose with no patient defects, springs to mind.
Following the depletion of the British Manufacturing Base, imports from the East have flooded the UK and indeed the Global Market---there are varying levels of Quality Control thus the emergence of large quantities of low grade and therefore ( in my view )un serviceable Component parts.
Any deflection from the 90 Degree and or the fourth part of a circle is unacceptable, send the lot back.
Buyer beware research your acquisitions before committing to a purchase order...