NUTS (AHE)

Question 1

Nuts for aircraft bolts and screws are manufactured in many sizes and shapes:

Answer 1

• Non−self−locking nuts;
• locking nuts;
• high−temperature self−locking nuts;
• low−temperature self−locking nuts

Question 2

These are used with drilled−shank or hex−head bolts, clevis bolts, eye bolts or strut and are designed to accommodate a cotter pin or wire-locking as a means of safetying

Answer 2

NON−SELF−LOCKING NUTS

Question 3

These nuts are available in cadmium−plated nickel steel, corrosion−resistant steel and in 2024 aluminum alloy.

Answer 3

Shear Castle Nut

Question 4

These nuts are designed to fit on standard airframe bolts and may be used when the bolt is subjected to either shear or tensile loads. They are made from the same material as the shear castle nut.

Answer 4

Castle Nut

Question 5

This nut is designed for use on an aircraft engine and is not approved for airframe use. It is made of heat−treated steel.

Answer 5

Slotted Engine Nut

Question 6

are intended for use on hose clamps and battery connections, etc, where the desired tightness is ordinarily obtained by the use of fingers. They are made of either cadmium-plated steel or brass.

Answer 6

Wing Nut

Question 7

a thin, plain nut which is tightened down firmly onto the main, plain nut. This friction wedges the threads to prevent them both slackening.

Answer 7

Lock Nut

Question 8

This nut has an unthreaded nylon insert permanently housed at the outer end. As the bolt threads engage the insert, the nylon is compressed into them, setting up a friction which prevents the nut unscrewing.

Answer 8

Nyloc Stiffnuts

Question 9

have six tongues at their outer end which are bent inwards to form a circle slightly less in diameter than the root of the bolt thread. As the bolt passes through the nut the tongues are pushed upwards, applying a locking load onto the bolt thread.

Answer 9

Oddie Stiffnuts

Question 10

These nuts have slotted locking extensions which are closed during manufacture to put the screw-thread out of alignment. As the bolt engages and realigns the extension thread, a grip is produced which provides a friction lock.

Answer 10

Aerotight and Philidas Stiffnuts

Question 11

is used when a slight range of movement is necessary to ensure the bolt can locate.

Answer 11

floating type anchor

Question 12

used when a row of anchor stiffnuts is required. In this arrangement, the stiffnuts are fitted at equal intervals along a channel strip which itself is riveted to the blind side of the structure.

Answer 12

strip nut

Question 13

In applications where temperatures exceed 120 C (25O F), all-metal locknuts are used. All−metal locknuts are constructed with either the threads in the locking insert out−of−phase with the load−carrying section, or with a saw−cut insert with a pinched−in thread in the locking section.

Answer 13

HIGH−TEMPERATURE SELF−LOCKING NUTS

Question 14

These should not be used in any location where the temperature will exceed 121 C (250 F). Fibre- or nylon-locknuts are constructed with an unthreaded fibre−locking insert held securely in place.

Answer 14

LOW−TEMPERATURE SELF−LOCKING NUTS