ASME B29-8:2002 pdf download LEAF CHAINS, CLEVISES, AND SHEAVES
1 LEAF CHAINS
1.1 Description
A leaf chain consists of a series of link platesalternately assembled with pins in such a way that thejoint is free to articulate between adjoining pitches.Typical assemblies are depicted in Figs. 1 and 2.
1.2 Numbering and Marking System
The chain described in this Standard shall carry theprefix BL. The last two digits of the number followingthe prefix denote the lacing. The right-hand digit designates the number of link plates in the articulating pitchThe digit to the left of this designates the number ofplates in the pin link pitch. The digits to the left ofthose two digits denote the number of eighths of aninch in the chain pitch.
EXAMPLE: BL523 indicates Type BL leaf chain, in. pitch witha 2 x 3 lacing; that is, two plates in the pin link pitch and threcplates in the articulating link pitch.
Chains shall be marked with the manufacturer’s nameor trademark.
1.3 Assemblies and General Proportions
Various assemblies and general proportions for leafchains are depicted in Fig. 3. Dimensions used in the
figures are as follows:CL = clearancepin diametermaximum pin diametermax.H = link plate height= 0.95PHmax= minimum width between pin link plates232chain pitch
hole diameter of articulating link platesapproximately Dmax.+ 0.0012 in.min.link plate thickness
maximum link plate thickness (based onmaX.normal steel tolerance). (See Table lA or1B for values or Tmax.)
W = width of chain over pin ends
Wmax.= Wmax.+ 0.5Dmax.
w = width over pin link plates
(Tmax. + CL) x number of link plates acrossWmax.1width of chain
NOTE: Style of heading pins is optional with the manufacturer.
1.4 General Chain Dimensions forInterchangeability
The dimensions given in Tables 1A and 1B provideguidance that will ensure interchangeability and compa-tibility with standard design clevises. It is recommended that these dimensions be considered for actual minimumand maximum limits.Manufacturers are responsible forthe actual dimensional features of their products.
NOTE: Chains from different manufacturers must never be placedtogether within the same application.
1.5 Minimum Ultimate Tensile Strength(M.U.T.S.)
Minimum Ultimate Tensile Strength (M.U.T.S.), forchain covered by this Standard, is the minimum forceat which an unused, undamaged chain could fail whensubjected to a single tensile loading test.(a) WARNING: The Minimum Ultimate TensileStrength is not a “working load.” The M.U.TS. greatlyexceeds the maximum force that may be safely appliedto the chain.
(b) Test Procedure: A tensile force is slowly appliedin a uniaxial direction, to the ends of the chain sample(c) The tensile test is a destructive test, Even thoughthe chain may not visibly fail when subjected to theMinimum Ultimate Tensile Strength, it will have beendamaged and will be unfit for service.
1.6 Tolerance for Chain Length
New chains may have a tolerance of +0.031 in./ft(258 mm/m) when measured under standard measuringload as outlined in para. 1.7.
1.7 Measuring Load
This is the load under which a chain is to bemeasured for length. It is equal to l% of the minimum
ASME B29-8:2002 pdf download
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