Although fasteners are low cost items, when fastener failures occur they can have a severe impact on
the economics of plant operations. It is increasingly important to deal effectively with materials and
corrosion problems even for low cost items such as threaded fasteners because of changes due to:
equipment upgrades; higher capital costs; water recycling; and, more aggressive process conditions.
This paper relates primarily to the use of stainless steel and specialty alloy threaded fasteners in pulp,
paper, biomass conversion and other industrial facilities, but references to carbon steel and low alloy
steel threaded fasteners are also included since these materials are used extensively throughout the
This paper discusses threaded fastener failure modes, design criteria of connections, specifications,
standards and identification markings. The term threaded fasteners is used in this paper to indicate all
forms of fasteners including bolts, studs, socket head cap screws, nuts, washers, etc.
Keywords: fastener, thread, nut, bolt, stud, screw, failure, socket-head, cap screw, torque, torque
wrench, washer, fatigue, corrosion fatigue, preload, proof load, clamping force, rolled thread, fastener