Downloaded from https://www.everyspec.com MIL-sTD-1312B FOREWORD 1. Background. The selection of fasteners in the design and construction fihase of weapons systems and equipments and the analysis of fasteners u8ed therein for parameters, such as suitability, standardization, and +jlification requires the evaluation and correlation of test data and:.~~; criteria. In evaluating these functions, it has become increasingly evident that the dats and criteria received from prime contractors, fastener producers, private laboratories, military docunents, and.rnilicaw laboratories cannot be adequately correlated.
The chief reason for this is the absence of unified standards prescribing test methods, procedures, fixtures, data analysis, and data presentation. ‘rbisdisparity encourages and often requires duplication of testing and reduces reliability.of ~ ~ , weapons systems and equipments, thereby impairing operations inv+ving erigineeringcontrol, design maintenance, quality assurance, standardizst$on, and,logistics simplification. TO correct this situation it was established that a unified set of test methods and procedures is required to serve as : i basic engineering tool for obtaining and presenting engineering data. As a result, this document was developed and prepared to satisfy this vital need.
This standard delineates standard test methods, procedures, conditions, fixtures, and methods of recording, analyzing and presenting test data. The purpose of the resulting test data is to determine the capability of fasteners to withstand the various environmental and meclianicalconditions encountered when used in military weapons systems. f Many benefits are to be expected by unified standard p Lts%%’Rieners. The following is a list of benefits that can be expected to accrue from using this standard. \ a. Availability of testing techniques and criteria necessary for the design and development of increasingly superior structural fasteners.
In the past, when a new fastener was needed to solve a problem, the necessary test procedures had to be developed and written; also, the macessary fixtures had to be designed. l’bisalways imposed delays, additional expenses, variations in test methods and in test results. b. Increasing incidence of correlation among fastener test data and design engineering techniques and design criteria for weapons systems and equipments.
As new systems are designed to achieve higher performance for a given volume and mass of material, it is essential that design data for structural joints (a large portion of which is obtained by testing fasteners) maintain a close correlation with engineering techniques and .: design criteria. Where weight is of importance, such as in aircraft structures, such close correlation will provide a substantial reduction in tie!ight . c. Availability of testing techniques and criteria necessary to mbintain consistent quality in the procurement of fasteners.