See also Torques and tightening sequence of cylinder head bolts for the K7M engine and for K4M
Universal tightening torque values based on fastener sizes
Most fasteners must be tightened to a specific torque. Tightening torque is the rotational force applied to a threaded part - a nut or bolt. Overtightening a fastener can weaken it and cause it to break, while undertightening it can eventually cause it to come loose. Bolts, screws and studs, depending on the material from which they are made and the diameter of their threads, have certain tightening torque values, many of which are given in the technical data. Please follow these guidelines carefully. For fasteners for which tightening torques are not given, a general table of tightening torque values is provided here as a guide. These tightening torque values are dry (unlubricated) fastening parts screwed into steel or cast iron (but not in aluminum). As mentioned earlier, the size and grade of the fastener determines the torque that can be safely applied to it. The figures given here apply to fasteners of class 2 and 3. Fasteners of higher strength classes can withstand higher tightening torque values
| Metric thread size | Nm |
| M6 | 9-12 |
| M8 | 19-28 |
| M10 | 38-54 |
| M12 | 68-96 |
| M14 | 109-154 |
| Pipe thread sizes | Nm |
| 1/8 | 7-10 |
| 1/4 | 17-24 |
| 3/8 | 30-44 |
| 1/2 | 34-47 |
How to tighten
If the fasteners are installed in a specific order, loosen and tighten them in a specific sequence to prevent the part from becoming distorted. Where this sequence is significant, it will be shown.
If the specific order of the bolts is not important, use the following rule to prevent misalignment:
First install the bolts or nuts and tighten them with your fingers. Then tighten each one one full turn, either crosswise or diagonally. Then, go back to the first piece and tighten them in the same sequence another half turn. Finally, tighten each one a quarter turn at a time until each fastener is tightened to the specified torque. To loosen and remove the fasteners, perform this procedure in reverse order.
To fix the thread, if necessary, special compounds are used (anaerobic fixatives) for threaded connections.
How to fix threaded connections
1 Grover. This is a spring split washer used as a locking element. Grovers cannot be used on deformable materials such as aluminum and its alloys, as well as on copper or bronze.
For more details, see the page: LadaMan.ru
2 Polymer insert. A bushing is inserted into a special groove, which is deformed when the nut is screwed onto the thread. Once tightened, the polymer insert increases friction, preventing possible loosening of the connection due to shaking. The disadvantage of such fasteners is the limited number of assembly/disassembly operations.
3 Bend-up washer. These washers are usually made of mild steel and are provided with tabs. One of the tabs is bent to the edge of the nut, which must be secured from unscrewing, and the other is fixed, if possible, on the part being tightened. It is clear that such parts are disposable.
4 Glue or cosmetic varnish. Nail polish or glue are often used as improvised means to lock threads. The main advantage of such techniques is their simplicity and the confidence that things won't get any worse. But these drugs do not work for their intended purpose, so you should not expect serious protection from them.
5 Split pin. A metal rod is inserted into the through hole and its ends are bent. As long as the cotter pin is in place, the nut will not come loose. It is clear that cotter pins can only be used with special nuts and bolts that have a hole. In addition, they will not help to fix the bolt or stud in the body of the part.
Nut with locking flange. Those who have dealt with the front hubs of a Zhiguli will probably remember the large nut, whose thin flange had to be bent into the grooves of the journal in two places. The disadvantage of this solution is the need for a special part such as a bolt and a rather rare nut.
Lock nut. The most primitive solution to combat self-loosening is lock nuts. The additional nut is pressed against the main one and locks it. This solution cannot be used everywhere - sufficient space is required on the threaded part of the stud or bolt.