Designations of bolts and nuts (Freelander 2)

All bolts or screws with ISO metric threads made of steel and with an outer diameter greater than 6 mm have the ISO M or M designation stamped on the head of the bolt.

In addition to the manufacturer's designation, the bolt head also has a strength index designation, for example: 8.8; 10.9; 12.9; 14.9. Some bolts have the designation M and the strength index stamped on the edges of the hexagon.

Bolts protected with anaerobic sealant (encapsulated)

An anaerobic sealant is applied to the threads of a bolt or screw in a special way during manufacture. These bolts can be identified by a colored ribbon that runs around the entire circumference of the bolt shaft, 360 degrees. Some types of sealant are transparent and almost indistinguishable from the outside, except for a slightly darker thread color where the sealant is applied to it. The anaerobic sealant is activated during the assembly process of the assembly, then hardens as a result of chemical transformations. This provides a secure fixation of the bolt against loosening.

Self-locking bolts

Self-locking screws and bolts (I mean bolts with nylon insert) can be reused provided that an increase in resistance to screwing is felt when starting to screw the insert bolt part.

Bolts and screws with a nylon insert are coated with or inserted into the threaded part of the sealant. These bolts can be identified by a colored insert that extends half the length of the bolt's shank, or by a colored plug inserted into the bolt.


Another type of self-locking bolts are bolts with threads that slightly mismatch the threads of the mating hole or nut into which the bolt is threaded.

CAUTION: DO NOT reuse self-locking bolts to assemble critical connections (engine bearings, flywheel bolts). Do not install conventional fasteners in place of the designed self-locking nuts, bolts or screws.

Type 2 self-locking bolts must not be used instead of bolts protected with anaerobic sealant (encapsulated).

Nut designation

Nuts with metric ISO threads and having a strength index of 8, 12 or 14 are indicated by applying the index to one of the ends of the nut or to one of the faces of the hexagon. Some nuts that have a strength index of 4, 5, or 6 also have a strength index designation. Part of the nuts may be marked with the symbol "M" on the end, which is opposite to the end with the applied strength index. This symbol indicates a metric thread.

Instead of indicating the strength index, the so-called "hourly" method of specifying the strength index. A mark is applied to the outer chamfer or end of the nut, which corresponds to the readings of the clock hands. Indications "hours" and are the designation of the strength index.


A dot is used to indicate the 12 o'clock mark, and (strength index values) notch is used. If the strength index is greater than 12, then a double dot is used to indicate the 12 o'clock mark.

When tightening "crown" nut with cotter pin slots, never loosen the nut to align the cotter pin holes. An exception is the case when this is provided for by the adjustment instruction. If you can't align the cotter pin holes, try replacing the washer or nut.

If the nut is used to control bearing preload, the nut must be tightened according to the tightening procedure.

Self-locking nuts

Unless otherwise specified, when the self-locking nuts are completely loosened, it is recommended to replace them with new ones of the same type and strength.