1.1 Nomenclature
The following definitions are illustrated in Fig. 1.
connecting link (cotter pin type): an outside link consisting of a pin link plate E, two assembled pins G—G, a detachable pin link plate D, and two cotters H—H.
double—pitch power transmission roller chain: a series of alternately assembled roller links and pin links in which the pins articulate inside the bushings, and the rollers are free to turn on the bushings. Pins and bushings are press fitted in their respective link plates.
offset link (cotter pin type): a link consisting of two offset link plates I—I, a bushing B, a roller C, a removable pin J, and cotter H.
pin link: an outside link consisting of two pin link plates E—E assembled with two pins F—F.
roller link: an inside link consisting of two roller link plates A—A, two bushings B—B, and two rollers C—C.
1.2 General Proportions
(a) The roller diameter is approximately /16 X pitch.
(b) The chain width is defined as the distance between roller link plates and equals approximately 16 X pitch.
(c) The pin diameter is approximately 32 X pitch or one-half of the roller diameter.
(d) The thickness of link plates is approximately 1/ x pitch.
(e) The maximum height of link plates is 0.475 x pitch.
1.3 Numbering System
The numerical identification and chain numbers will be obtained by numerically adding 2000 to the standard base series chain number.
EXAMPLE: Chain No. 2040 (1 in. pitch) has double the pitch of Chain No. 40 (‘ in. pitch), but uses the same pins, bushings, and rollers.
1.4 Chain Strength Requirements
1.4.1 Minimum Ultimate Tensile Strength
(a) Single strand chains meeting the requirements of this Standard will have a minimum ultimate tensile strength equal to or greater than the values listed in Table 1A or lB.
(b) Minimum ultimate tensile strength (M.U.T.S) for chain covered by this Standard is the minimum force at which an unused, undamaged chain could fail when subjected to a single tensile loading test.
WARNING: The minimum ultimate tensile strength is NOT a “working load.” The M.U.T.S. greatly exceeds the maximum force that may be applied to the chain.
(1) Test Procedure. A tensile force is slowly applied at a rate not to exceed 2.0 in./min (50.8 mm/mm), in a uniaxial direction, to the ends of the chain sample.
(2) The Tensile Test Is a Destructive Test. Even though the chain may not visibly fail when subjected to the minimum tensile force, it will have been damaged and will be unfit for service.
1.4.2 Chain PreLoading. Chains conforming to this Standard shall be preloaded during manufacturing by applying a tensile force equal to a minimum of 30% of the M.U.T.S. given in Table 1A or lB.
1.5 Tolerance for Chain Length
New chains, under standard measuring load, shall not be underlength. Overlength tolerance is 0.016 in./ft (1.33 mm/rn).
1.6 Measuring Load
Measuring load is the load under which the chain is to be measured for length. It is equal to 1% of the minimum ultimate tensile strength, with a minimum of 31 lb (138 N). Length measurements are to be taken over a length of at least 12 in. (300 mm).
1.7 General Chain Dimensions
See Tables IA and lB.
1.8 Dimensional Limits for Interchangeability
To assure interchangeability of links produced by different makers of chain, the following standard maximum and minimum dimensions are adopted. They are not the actual dimensions to be used in manufacturing but rather the limiting dimensions, maximum and minimum, within which it is necessary to keep to assure the desired interchangeability.