TM9-2330-202-14&P - JATONKAM35s HOME ON THE WEB

TM 9-2330-202-14&PH-4.TIGHTENING METAL FASTENERS (continued).STATED RANGETable H-3. Torque RangesMOST EFFECTIVE RANGE0-600 ft-lb 150-450 ft-lb0-170 ft-lb 44-131 ft-lb15-75 ft-lb 30-60 ft-lbH-5.FASTENER SIZE AND THREAD PATTERN.Threaded fasteners are categorized according to diameter of the fastener shank. Thread styles are divided into broadgroups, the two most common being coarse (Unified Coarse-UNC) and fine (Unified Fine-UNF). These groups aredefined by the number of threads per Inch on the bolt shanks. In addition, threads are categorized by thread class(Table H-4), which is a measure of the degree between threads of bolt or screw (external threads) and threads of theattaching nut or tapped hole (internal threads of the attaching nut or tapped hole) (internal threads). The most commonthread class for bolts and screws is Class 2.Table H-4. Thread Classes and DescriptionEXTERNAL INTERNAL INTERNAL1A 1B LOOSE FIT2A 2B MEDIUM FIT3A 3B CLOSE FITH-4