A Guide to Aerospace Studs Not Named Maverick or Iceman
Before we explain what aerospace studs are (and are not), we must cover a few terms. First: fasteners. Fasteners include bolts, screws, studs, nuts and rivets. The one and only purpose of any fastener is to clamp parts together. They are not meant to position aircraft parts relative to one another, or to function as axles, pivots or fulcrums. Aerospace fasteners clamp two parts together. Period.
Fasteners are differentiated not so much as by what they do but by how they function. While screws are headed, externally threaded fasteners that are threaded into the material they will hold, bolts are headed fasteners are made to meet an exact thread specification so they can accept a non-tapered nut.
Aerospace studs are a combination — a hybrid — between a bolt and a screw. One end of a stud functions as a bolt and the other functions as a screw.
When are Aerospace Studs Used?
Aerospace studs are the preferred fastener in many heavy-duty applications, from propulsion systems to helicopters. Because they do not rotate during tightening — the nut is tightened instead — studs make it easier to achieve highly accurate torque values and reduce the chance of the main cap walking. For the same reason, studs also cause less wear and tear to the block’s threads and thereby extend its serviceable life.
Types of Aerospace Studs
Four general types of aerospace studs are used in structural applications in aircraft: coarse thread (NAS183, for example), fine thread (NAS184, for example), lockring studs (MS51551, for example), and stepped studs. Stepped studs have a different thread on each end of the stud. Fine thread, lockring, and coarse thread studs have identical threads on each end.
Studs are either drilled or undrilled at the nut end. Both fine thread studs and coarse studs are made from alloy steel and must be heat treated. The AS7481, for example, is used primarily in aerospace propulsion system applications thanks to its excellent creep resistance and resistance to stress rupture. It is heat treated after the threads are rolled. Lockring studs include a lockring that prevent it from failing due to stress, extreme vibration or drastic variations in temperature.
Procure Aerospace Studs from Aerospace Manufacturing
Aerospace Manufacturing is a AS9100 and ISO:9001 accredited, QSLM approved manufacturer of high strength, close tolerance fasteners made to all standards. We also create custom specials made to print.