Designations of bolts and nuts (Freelander 2)

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

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 strength index stamped on the hexagon faces.

Bolts protected with anaerobic sealant (encapsulated)

Anaerobic sealant is applied to the threads of a bolt or screw in a special way during manufacturing. These bolts can be distinguished by a colored strip that runs around the entire circumference of the bolt shaft, for all 360 degrees. Some types of sealant are transparent and almost invisible, except for the slightly darker color of the threads where the sealant is applied. Anaerobic sealant is activated during the assembly process, then hardens as a result of chemical transformations. This ensures reliable fixation of the bolt from unscrewing.

Self-locking bolts

Self-locking screws and bolts (meaning bolts with a nylon insert) can be reused provided that an increase in tightening resistance is felt when the insert portion of the bolt is first tightened.

Nylon insert bolts and screws have a sealant applied or inserted into the threaded portion. These bolts can be identified by a colored insert that extends halfway around the bolt shank or by a colored plug inserted into the bolt.

Another type of self-locking bolt is a bolt with a thread that is slightly out of alignment with the thread of the counter hole or nut into which the bolt is screwed.

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

It is prohibited to use self-locking bolts of the second type instead of bolts protected with anaerobic sealant (encapsulated).

Designation of nuts

(The article was taken from this resource: www.lrman.ru)


Nuts with metric ISO threads and strength index 8, 12 or 14 are designated by applying the index to one of the ends of the nut or to one of the hexagon faces. Some nuts with strength index 4, 5 or 6 also have a strength index designation. Some nuts may be designated by the symbol "M" on the end opposite the end with the strength index. This symbol designates metric threads.

Instead of indicating the strength index, the so-called "clock" method of indicating the strength index is sometimes used. A mark is applied to the outer chamfer or end face of the nut, which corresponds to the readings of the clock hands. The "clock" readings are the designation of the strength index.

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

When tightening a crown nut that has slots for a cotter pin, never loosen the nut to align the holes for the cotter pin, unless specified in the adjustment instructions. If you cannot align the holes for the cotter pin, try replacing the washer or nut.

If the bearing preload is adjusted using a nut, the nut must be tightened in accordance with 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.