ASTM F939-2018 pdf free download

ASTM F939-2018 pdf free download.Standard Practice for Selection of Release Torque Values for Alpine Ski Bindings
1. Scope
1.1 This practice provides procedures for the selection of release torque values for Alpine ski/boot/bindings systems. These procedures may be used by ski binding manufacturers in their instructions for installation and use and by ski shops for the adjustment of already mounted ski bindings. 1.2 This practice is applicable to releasable Alpine ski/boot/ binding systems. 1.3 Release torque values selected using this practice may not be appropriate for circumstances in which: 1.3.1 The skier carries an object that significantly increases the skier’s effective body weight, 1.3.2 The skier grasps or in some manner controls an object such as a sled, or 1.3.3 The skier encounters exceptional snow or terrain conditions not commonly found on developed ski slopes. 1.4 This practice may be inappropriate for non-mechanical bindings or bindings used with boots that reach more than half way up the lower leg. 1.5 Release torque values outside the recommendations of this practice may increase the risk of injury to the skier. However, skiers who are informed of this potential risk may request such settings and have them provided, subject to any guidelines and limitations specified by the binding manufac- turer. 1.6 These values refer to recommended release torque for initial adjustment ofa ski binding and subsequent readjustment of the binding during routine maintenance or following a suspected malfunction. However, these values are not intended to apply to the condition of the equipment at any time after it is put into use. 1.6.1 For information concerning applicable tolerances to be used for the adjustment and inspection of releasable Alpine ski bindings in retail operations consult Practice F1063; for rental applications consult Practice F1064. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.8 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 release/retention settings—release torque of the ski/ boot/binding system in twist (M z ) and forward lean (M y ) as defined in Test Method F504. 3.1.2 skier type—classification selected by the skier for the type of skiing to be undertaken. 3.1.2.1 I—designation that provides lower than average release/retention settings; corresponds to an increased risk of inadvertent binding release in order to gain releasability in a fall; also applies to entry-level skiers uncertain of their classification. 3.1.2.2 II—designation that provides average release/ retention settings appropriate for most recreational skiing; applies to skiers not classified as in Type I or III. 3.1.2.3 III—designation that provides higher than average release/retention settings; corresponds to decreased releasabil- ity in a fall in order to gain a decreased risk of inadvertent binding release. 3.1.3 (/)—symbol that separates skier type designations; used when, as a result of troubleshooting, different skier types have been selected for determining twist (M x ) and forward lean (M y ) release/retention settings; shown in the order (twist/ forward lean) or (T/H) to denote toe piece (T) and heel piece (H) of the ski binding. Other conventions may be used to record different skier types for twist and forward lean when required by the documentation. N OTE 1—See Appendix X2 for examples of other definitions of skier type. 3.1.4 normal settings—release/retention settings derived through the use of Skier Types I, II, and III. 3.1.5 discretionary settings—release/retention settings higher or lower than the normal setting range 3.1.5.1 (–)—symbol that when placed to the left of Type I provides release/retention settings lower than Type I; corre- sponds to a further increase in the risk of inadvertent binding release in order to gain increased releasability in a fall.