Overlaps a lot in concept with a parts list (PL or P/L). Same definition as the bolt circle diameterĪlso called a list of materials (LM or L/M). In modern practice basic dimensions have a rectangular box around them, or sometimes the word "BASIC". Thus they are instead given as basic dimensions. A common and simple example is hole location: If a hole's centerpoint location has a position tolerance, then the centerpoint's coordinates do not need (and should not have) separate tolerances applied to them. The reason why a basic dimension does not carry a tolerance is that its actual value will fall (acceptably) wherever it is put by other features' actual values, where the latter features are the ones with tolerances defined. It is thus similar in some respects to a reference dimension. It does not serve as an acceptance criterion. Maintains technical standards, especially regarding materials science and engineering and metrology.Ī basic dimension is one that is the theoretical value without any tolerance range.
Referring to an assembly of parts rather than just one (sub)part ("piece part", "detail part").įormerly the American Society for Testing and Materials now ASTM International Therefore, smaller companies will often cite larger companies' lists in order to avoid the cost of duplicating the effort.Īnd the many standards that it issues, for example, ASME Y14.5. Vetting the companies on this list requires the CDA to audit (and possibly periodically re-audit) the companies, which incurs an overhead expense for the CDA. The list of such companies (which usually changes over time) is called an APSL, AVL, or similar names. When only certain companies are approved by the CDA to manufacture the product (that is, to make what the drawing depicts/defines), they are called by names such as "approved supplier", "approved product supplier", "approved vendor", or "approved product vendor". Australian Standards, standards per Australian industry.Īpproved product supplier, approved vendor, approved-product-supplier list, approved-vendor list Standard aerospace hardware sometimes has the AS- prefix in the catalog numbers. Aerospace Standards, technical standards maintained by SAE International and widely used in the aerospace manufacturing industries. For example, in an assembly with a bolted joint using four bolts, the PL quantity column will say "4" for the bolt PN, "4" for the nut PN, and "AR" for the liquid threadlocker that will be applied.Īerospace Standards Australian Standardsġ. The intelligence behind defining AQLs is in figuring out how much error is tolerable given the costs that would be incurred by any efforts to further reduce its incidence.Īn abbreviation used in parts lists ( PLs, LMs, BoMs) in the quantity-per-assembly field when a discrete count is not applicable. It is trivial to say that no one wants any error, and that everyone wants uniform perfection but in the real world, it almost never happens. The threshold of defectiveness that is allowable in a group of parts. (See also MS- and NAS.)Īnd the many standards that it issues, for example, ANSI Z87.1. DOD and military to do less of it (as explained at United States Military Standard > Origins and evolution), although many MIL standards are still current.
#Met standard notes engineering grapics iso
Today industry and ISO also do a lot of this standardization specification, freeing the U.S. Army and Navy were leading the way on product standardization for logistics improvement, yielding the United States Military Standards system. Came from the era of circa 1890s-1945, when the U.S. Standards in materials science and engineering maintained by SAE International and widely used in the aerospace manufacturing industries.Ī prefix for standard hardware (catalog hardware) ID numbers. The SAE steel grade system was formerly a joint AISI-SAE system.
The AISI acronym is commonly seen as a prefix to steel grades, for example, "AISI 4140". Example would be the top of a coffee table to the shag of the carpet, not where the bottom of the tables feet dig in. Commonly used when measuring the corners of a hex drive, such as a hex nut.Ĭommonly used when measuring the flat surfaces of a hex drive, such as a hex nut.Ī dimension that establishes a distance away from the finished floor.
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