GENERAL INFORMATION
4
GENERAL PRECAUTIONS AND FITTING INSTRUCTIONS
Nut identification
A nut with an ISO metric thread is marked on one
face or on one of the flats of the hexagon with the
strength grade symbol 8, 12, or 14. Some nuts with
a strength grade 4, 5 or 6 are also marked and some
have the metric symbol M on the flat opposite the
strength grade marking.
A clock face system is used as an alternative
method of indicating the strength grade. The
external chambers or a face of the nut is marked in a
position relative to the appropriate hour mark on a
clock face to indicate the strength grade.
A dot is used to locate the 12 o’clock position and a
dash to indicate the strength grade. If the grade is
above 12, two dots identify the 12 o’clock position.
Locking devices
Always release locking tabs and fit new locking
washers, do not re-use locking tabs. Always use a
backing spanner when slackening or tightening
brake and fuel pipe unions.
Fitting a split pin
Always fit new split-pins of the correct size for the
hole in the bolt or stud. Do not slacken back nut to
enter split-pin.
Always fit new roll pins of an interference fit in the
hole.
Always fit new circlips of the correct size for the
groove.
Self-locking nuts
Self-locking nuts, i.e. nylon insert or metal stiff nuts
can be re-used providing resistance can be felt
when the locking portion of the nut passes over the
thread of the bolt or stud.
To Next Page
Loading...
