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Questions tagged [standards]

77 questions
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Schematic Diagrams for Mechanical Systems

Is there some sort of equivalent standardized schematical (topological) diagram -such as Piping and Instrumentation Diagram, Electrical Schematics, Process Flow Diagrams, etc.- for the realm of mechanical engineering? I just need to draw the overall…
joojaa
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(de facto) Standards for freehand technical lettering?

What de facto standards or otherwise exist that prescribe a style for freehand technical lettering? With the ubiquity of CAD there is probably a diminished need for standardized handwriting. Technical lettering was not part of my undergraduate…
ebpa
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I-beam annotation for tube on drawing

I have been sent a clip of a drawing with the following annotations on it, but I've never seen them before and can't figure out what they mean. Is there a standard interpretation of these callouts? Initially I thought that they might be some…
Ethan48
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1 answer

How deep are utilities typically buried?

What are the recommended or relevant standards for US city planning with regards to depth ranges for various utilities such as water, natural gas, and power, as well as for subway or rail, etc...? For example, water and gas lines should be buried…
Atomiklan
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Uncertainty Calculation of LVDT displacement transducers for length measurement

I have to calculate the uncertainty of measurement for an LVDT Linear displacement transducer used for measuring length. Uncertainty calculations are ruled by ISO 17025 but there are no (at least haven't found) specific guidelines for the…
spe4ker
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LO/LC, CSO/CSC Valve Definition

Does any one here know of an authoritative source (ASME, ISA, NFPA, OSHA, etc..) that gives a definition for the following in one of their standards or codes and the number for that standard or code: LO (Valve Locked Open) LC (valve Locked…
Jrican
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What organization specifies unit of measure conversions?

A recent work project involved a number of unit conversions between various systems of measurements. Due to the scale and critical nature of the project, we wanted to ascertain that our conversion factors were as accurate as possible. While only…
user16
3
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2 answers

What ASTM standard would be appropriate for testing the breaking strength of nylon ropes

ASTM D4268-93 would appear to be the relevant testing standard, but this was withdrawn in 2002 and is no longer active. Is there a current standard?
user8908459
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What does the D stand for in the steel grade 16MND5

I would like to know what does the "D" means in steel grade 16MND5. According to the standard EN 10027: 16 means 0.16 % C MN 5 means 1.25 % Mn (5 must be divided by 4 to get the Mn mass fraction) But nothing is specified for D.
Stellarator
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Industry standard for AC wall electrical box space

Are there any industry standards (Engineering Specifications) for the minimum / maximum space required for the electrical box that holds a regular AC wall plug? The problem I am trying to solve is quite simple - are / is there any local (USA,…
KingsInnerSoul
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What thread could this camera motor be?

Firstly, I am sorry that the title of this question isn't helpful. I have bought these motors for a project: 5V 7mm 2 Phase 4 Wire Stepper Motor I assumed that the 1.7mm diameter threaded shaft would take an M1.7 nut, but it does not. Standard…
JB515
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Normative Document for 'Grade 520' Steel

I am specifying a product made in Australia, which is made of "Grade 520 Steel." The manufacturer of the product lists a minimum yield stress of 520 N/mm² (75,400 psi) and a minimum ultimate stress of 650 N/mm² (94,300 psi) with a minimum elongation…
Ethan48
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EU EN standard 1822 vs US HEPA filters

There's a EU EN standard 1822 for air filters that has seen several iterations. The pre-2009 versions of EN 1822 (which seems to have come out in 1998) were pretty confusing as they allowed poorer filters to be labeled as H or HEPA; e.g. a "HEPA…
got trolled too much this week
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GD&T for Multiple Surfaces as Single Feature

I'm looking to get some collective agreement on a question that I have come across a few times now. When referring to features that are technically independent, what is the general consensus on dimensioning them? Take, for example, the part…
Argonax
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Which vibration standard is the most common for transported packages?

There are several standards which all are valid when it comes to mechanical shock, bump and vibration, both for products in use and packaged and being transported. Here are a few: ISO 13355:2001 - Packaging -- Complete, filled transport packages…
winny
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