BS EN 3389:2009 pdf free download – Aerospace series – Fasteners, externally threaded, in heat resisting nickel base alloy NI- PH1302 (Waspaloy) Classification: 1 210 MPa/730 °C – Manufacturing method optional一Technical specification.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
production batch
quantity of finished parts fabricated by the same process from a single material cast (single heat of alloy), having the same basic part number and diameter, heat treated together to the same specified condition and produced as one continuous run
3.2
inspection lot
quantity of parts from a single production batch of the same part number which completely defines the part
3.3 Surface discontinuities
3.3.1
crack
rupture in the material which may extend in any direction and which may be intercrystalline or transcrystallyne in character
3.3.2
seam
longitudinal surface defect in the form of an unwelded open fold in the material
3.3.3
lap
surface defect caused by folding over metal fins or sharp corners and then rolling or forging them into the surface
3.3.4
inclusion
non-metallic particles originating from the material making process; they may exist as discrete particles or strings of particles extending longitudinally
3.4
test temperature
ambient temperature, unless otherwise specified
3.5
simple random sampling
the taking of n items from a population of N items in such a way that all possible combinations of n items have the same probability of being chosen
[ISO 3534, see definition]
3.6
critical defect
defect that according to judgment and experience, is likely to result in hazardous or unsafe conditions for individuals using, maintaining, or depending upon the considered product or that is likely to prevent performance of the function of a major end item
[ISO 3534, see definition]
3.7
major defect
defect other than critical, that is likely to result in a failure or to reduce materially the usability of the considered product for its intended purpose
[ISO 3534, see definition]
3.8
minor defect
defect that is not likely to reduce materially the usability of the considered product for its intended purpose, or that is a departure from established specification having little bearing on the effective use or operation of this product
[ISO 3534, see definition]
3.9
sampling plan
plan according to which one or more samples are taken in order to obtain information and possibly to reach a decision
[ISO 3534, see definition]
3.10
limiting quality
LQ10
in a sampling plan, a quality limit which corresponds to a specified and relatively low probability of acceptance in this case 10 % probability of acceptance; it is the limiting lot quality characteristic that a lot of this quality would occur
When expressed as a per cent defective, it may be referred to as a lot tolerance per cent defective [ISO 3534, see definition]
acceptable quality limit
AQL
quality limit which in a sampling plan corresponds to a specified but relatively high probability of acceptance; it is the maximum per cent defective (or the maximum number of defects per hundred units) that, for purposes of sampling inspection, can be considered satisfactory as a process average
[ISO 3534, see definition].