ISO 5858:1999 pdf download – Aerospace -Nuts, self-locking, with maximum operating temperature less than or equal to 425 C -Procurement specification.
non-metallic paritcles originating from the material manutactunng process
NOTE These particles may be isolated or arranged in strings.
critical defect
defect that, according to judgernent and experience, is likely to result in hazardous or unsate conditions for individuals using, maintaining, or dependmg upon the considered prodect, or that is likely to prevent performance of the function of a major end item
major defect
detect, other than critical, that is likely to result In a failure or to reduce materially the usabilIty 01 the considered product for Its intended purpose
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
sampling plan
plan according to which one or more samples are taken in order to obtain information and possibly reach a decision
NOTE For the purposes of this International Standard, sacli sampling plan specifies the nuner of nuts to be inspected as a function of the size of the batch and the acceptance number Inumber of detective items acceptable (Ac)131.
simple random sampling
sampling of ,* items from a population of ,v items in such a way that all possible combinations of n items have the same probability of being chosen
acceptance quality limit
maximum percent defective (or the maximum number of detects per hundred units) that. for purposes of sampling inspection, can be considered satisfactory as a process average
NOTE Variant: quality level which in a sampling plan corresponds to a specified but relatively high probability of acceptance.
limiting quality
sampling plank quality level which corresponds to a specified and relatively low probability of acceptance
NOTE I It is the limiting lot duality characteristic that the consumer is willing to accept with a low probility that a lot oJ this quality would occur.
NOTE 2 For the purposes of this International Standard, the limiting quality given in Table 12 corresponds to a consumer’s risk of 10%.
self-locking torque
torque to be applied to the nut or bolt to maintain Its movement of rotation in relation to the associated pan, the assembly being under no axial load and the nut-locking system being completely engaged witti the bolt (two pitches minimum protrusion, including the end chamfer)
seating torque
tightening torque to be applied to the nut or bolt to introduce or to Increase the axial load in the assembly
unseating torque
uritightening torque to be applied to the nut or bolt to reduce or remove the axial load in the assembly
breakaway torque
torque required to start unscrewing the nut or bolt with respect to the associated part, with the nut-locking device still fully engaged on the bolt, but alter the axial load in the assembly has been removed by unscrewing half a turn lollowed by a halt in rotational movement
wrench torque
tightening and untlghtening torques wbich the driving feature of the nut has to withstand repeateIy without any permanent deformation which would prevent the appropriate wrench from being used or preclude re-use of the nut
4 Quality assurance
4.1 General
4.1.1 Manufacturer’s approval
The manufacturer shall conform to the quality assurance and approval procedures defined by ISO 9002.
The purpose of these procedures is to ensure that a manufacturer has a quality system and the capability for continuous production of nuts complying with the specified quality requirements.
Approval of the manufacturer shall be granted by the Certification Authorities, or their appointed representative, who may be the prime contractor,
4.1.2 QualificatIon of nuts
the purpose of quablication inspections and tests of nuts is to check that the design and manufacturing conditions br a nut allow ii to satisfy the requirements of this International Standard.
Qualification of the nuts shall be granted by the Certification Authorities m the purchasers country, or their appointed representative, who may be the prime contractor.
4.1.3 Production acceptance of nuts
The purpose of production acceptance inspection and tests of a nut is to check, as simply as possible, using a method which is inexpensive but the most representative of the actual conditions of use, with the uncertainty inherent in statistical sampling, that the nuts satisfy the requirements of this International Standard,
Production acceptance inspections and tests shall be carried out by the manufacturer, or under his responsibility. The manufacturer is responsible for the quality of the nuts manufactured.