TM-9-2330-326-14-P

SEMITRAILER, TACTICAL, DROP DECK BREAKBULK/CONTAINER TRANSPORTER, 22-1/2 TON, M871A3

TECHNICAL MANUAL; OPERATOR’S, UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST)

FEBRUARY 2006

TM-9-2330-326-14-P - Page 277 of 540

TM 9-2330-326-14&P

H-23

H-7.

FASTENER SIZE AND THREAD PATTERN

Threaded fasteners are categorized according to diameter of the fastener shank. Thread styles are

divided into broad groups, the two most common being coarse (Unified Coarse–UNC) and fine (Unified

Fine–UNF). These groups are defined by the number of threads per inch on the bolt shanks. In

addition, threads are categorized by thread class, which is a measure of the degree between threads

of the bolt or screw (external threads) and threads of the attaching nut or tapped hole (internal threads

of the attaching nut or tapped hole) (internal threads). The most common thread class for bolts and

screws is Class 2.