ISO 9154:2016 Aerospace —ボルト、MJスレッド、耐熱ニッケル基合金製、強度クラス1 550 MPa —調達仕様 | ページ 2

3.1

batch

quantity of finished products, manufactured using the same processes, from a single material cast (single heat of alloy) having the same definition document number, diameter, and length code, heat treated together to the same specified condition and produced as one continuous run

3.2

inspection lot

quantity of bolts products from a single production batch (3.1) having the same definition document number

3.3

definition document

document specifying directly or indirectly all the requirements for products

Note 1 to entry: The definition document may be an International Standard, an in-house standard, or a drawing.

3.4

crack

rupture in the material which may extend in any direction and which may be intercrystalline or transcrystalline in character

3.5

seam

longitudinal open surface defect

3.6

lap

surface defect caused by folding over metal fins or sharp corners and then forming them into the surface

3.7

crevice

hollow area at thread crest

3.8

inclusions

non-metallic particles originating from the material manufacturing process

Note 1 to entry: These particles may be isolated or arranged in strings.

3.9

microstructural shearing

shear banding

V- or U-shaped rippled grain structure immediately below the thread root or chevron-shaped rippled grain structure within the thread crest

3.10

sampling plan

plan according to which one or more samples are taken in order to obtain information and possibly to reach a decision, if possible

Note 1 to entry: In this International Standard, each sampling plan defines the number of bolts to be inspected as a function of the size of the batch and the acceptance number [number of defective items acceptable (Ac)] ¹

3.11

simple random sampling

sampling 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

3.12

critical defect

defect that, according to judgement 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

3.13

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

3.14

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 specifications having little bearing on the effective use or operation of this product

3.15

limiting quality

LQ

<sampling plan> a quality level which corresponds to a specified and relatively low probability of acceptance

Note 1 to entry: It is the limiting lot quality characteristic that the consumer is willing to accept with a low probability that a lot of this quality would occur.

Note 2 to entry: For the purposes of this International Standard, the limiting quality quoted in Table 4 corresponds to a probability of acceptance of 10 %.

3.16

acceptable quality limit

AQL

maximum percent defective (or the maximum number of defects per hundred units) that, for purposes of sampling inspection, can be considered satisfactory as a process average

Note 1 to entry: Variant: Quality level, which in a sampling plan, corresponds to a specified but relatively high probability of acceptance.