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Fundamentals of Threaded Fasteners

Fastener experts believe that upwards of 95% of all fastener failures are the result of either the wrong fastener for the job or improper installation. Improper installation or incorrect fastener selection can result in catastrophic loss or damage. Learn how to avoid issues by getting the answers in this course.
Standard

Alignment of Nut Slots

1990-01-01
CURRENT
J484_199001
This method of gaging alignment of nut slots allows equal variations for location of the cotter pin hole in the bolt and location of slots in the nut. To inspect the nut, the slotted gage is inserted through the nut hole from the bearing surface of the nut. Alignment of slots is considered satisfactory if the gage pin can be slipped into the gage and nut slots without interference.
Standard

Round Head Bolts

1990-01-01
CURRENT
J481_199001
Round head bolts are made in two body styles: (a) A full size body, with a maximum diameter somewhat greater than the nominal diameter (not an SAE Standard except for ribbed neck bolts, Table 3); and (b) an undersize body, with a minimum diameter approximating the pitch diameter of the thread and a maximum diameter never exceeding nominal (SAE standard for all types except ribbed neck bolts). The body diameter of either style may be exceeded by a reasonable swelling or fin under the head, or under corners of the square necks, to the extent that serviceability is not affected.
Video

Monitoring NO2 Production of a Diesel Oxidation Catalyst

2012-01-24
A combination of laboratory reactor measurements and vehicle FTP testing has been combined to demonstrate a method for diagnosing the formation of NO2 from a diesel oxidation catalyst (DOC). Using small cores from a production DOC and simulated diesel exhaust, the laboratory reactor experiments are used to support a model for DOC chemical reaction kinetics. The model we propose shows that the ability to produce NO2 is chemically linked to the ability of the catalyst to oxidize hydrocarbon (HC). For thermally damaged DOCs, loss of the HC oxidation function is simultaneous with loss of the NO2 production function. Since HC oxidation is the source of heat generated in the DOC under regeneration conditions, we conclude that a diagnostic of the DOC exotherm is able to detect the failure of the DOC to produce NO2. Vehicle emissions data from a 6.6 L Duramax HD pick-up with DOC of various levels of thermal degradation is provided to support the diagnostic concept.
Video

Tailored Conversion Coatings for Enhanced Adhesion to Metal

2012-03-21
As a result of recommendation from the Augustine Panel, the direction for Human Space Flight has been altered from the original plan referred to as Constellation. NASA's Human Exploration Framework Team (HEFT) proposes the use of a Shuttle Derived Heavy Lift Launch Vehicle (SDLV) and an Orion derived spacecraft (salvaged from Constellation) to support a new flexible direction for space exploration. The SDLV must be developed within an environment of a constrained budget and a preferred fast development schedule. Thus, it has been proposed to utilize existing assets from the Shuttle Program to speed development at a lower cost. These existing assets should not only include structures such as external tanks or solid rockets, but also the Flight Software which has traditionally been a ?long pole? in new development efforts. The avionics and software for the Space Shuttle was primarily developed in the 70's and considered state of the art for that time.
Video

Ionic Liquids as Novel Lubricants or Lubricant Additives

2012-05-10
For internal combustion engines and industrial machinery, it is well recognized that the most cost-effective way of reducing energy consumption and extending service life is through lubricant development. This presentation summarizes our recent R&D achievements on developing a new class of candidate lubricants or oil additives ionic liquids (ILs). Features of ILs making them attractive for lubrication include high thermal stability, low vapor pressure, non-flammability, and intrinsic high polarity. When used as neat lubricants, selected ILs demonstrated lower friction under elastohydrodynamic lubrication and less wear at boundary lubrication benchmarked against fully-formulated engine oils in our bench tests. More encouragingly, a group of non-corrosive, oil-miscible ILs has recently been developed and demonstrated multiple additive functionalities including anti-wear and friction modifier when blended into hydrocarbon base oils.
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