2.1.7 lockpinx and collars: a headed and externally grooved mechanical device designed for insertion through holes in a.ssemhled parts. A cylindrical collar is swaged into the external groove as the lock pin is hydraulically tensioned. Collars are either smooth bored or may contain a lit-tab. An optional flange provides a built-in washer.
2.1.8 mechanical properties: identify the reaction of a fastener to applied loads. Rarely arc the mechanical properties of the fastener those of the raw material from which it was made. Properties such as tensile and yield strengths. hardness, and ductility will vary widely. depending upon choice of manufacturing methods and metallurgical treatments.
2.1.9 modified standard: a part that is standard with one or more of its features or characteristics slightly changed. Such a part is normally ordered to a customer’s print is used by that customer in a particular application. but thc part is such that any interested manufacturer can produce it.
2.1 .10 nonstandard fastener or special fastener: a fastener that differs in size, length. configuration. material, or finish from established and published standards.
2.1.11 phy.cical properties: inherent in the raw material and remain unchanged, or with only slight alteration iii the fastener following manufacture. Such properties are density, thermal conductivity, and magnetic susceptibility.
2.1.12 Part Identfving Nianber (PIN): a 21 -character code that identifies an ASME B 18 manufactured product by specific characteristic fields such as fastener family identification. B18 standard identification, fastener style or type. thread series, nominal diameter, nominal length or dimensional/other characteristics, material and treatment. plating. coating, and passivation and special features relevant to the fastener product.
2.1.13 precision fastener: manufactured to close dimensional and geometric tolerances.
2.1.14 proof load: a tensile load that the fastener must support without evidence of permanent deformation. Proof load is an absolute value, not a maximum or minimum value. For most carbon or alloy steel fastener strength grades or property classes, proof loads are established at approximately 90 to 93% of the cxpectcd minimum yield strength. Proof loads arc frequently used as design values in joint analysis and fastener select ion.
2.1.15 pnwf ;e,ci: a form of iensile test where the maximum load applied is the proof load value in the applicable specification.
2.l.l6fartener quality: the accuracy of manufacture of the fastener such that it conforms to its specilied tolerances. limits. and requirements.
2.1.17 airrraft/ciero.puce fasttncr: intended for use in a flying vehicle.
2.1.18 fit: the amount of clearance or interference bciwcen mating parts.
2.1.19 .shear Jiixwn’r: a fasener whose primary junction is to resist forces applied at a right angle to the fastener axis that tend to shear it.
2.1.20 .cuindarti frLctcszt’r: can be described 1mm nationally recognized consensus standards documents and may be produced by any interested manufacturing facility.
EXAMP1i: An order that %pecities ‘—I3 X 2 LJNC-2A He Cap Scrc, SAF. 3429 Grade 5. .hould rc.uh in thc Wentical product being del,ertd by rny b%tcner i mufacturer accepting the ordcr, Often it is said that a %tandard fastener could be ondered by phone and the identical product recci’ed tram multiple ourccs
All other fasteners would be classified as SPECIAL or NONSTANDARD and would properly fall into three groups:
(a) modified standard
(b) proprietary—patented
.) engineered special parts
Generally these will require a written description and/ or blueprint or drawing to communicate what exactly is required.
2.1.21 stock fi.siener: commercially available in a quantity from a manufacturer or distributor of fasteners.
2.1.22 .tuhsuandardfasuicr: does not meet its specified requirements related to fit, form, or function.