PEINER High Strength assemblies are delivered ready for installation, galvanized nuts are lubricated with a molybdenum coating (the black, non-galvanized version is lightly lubricated with oil),
PEINER High Strength, nuts and washers should not be additionally lubricated,
additional lubrication of bolts, nuts and washers changes the clamping force and causes installation failures,
hot-dip galvanized PEINER High Strength nuts should be used only with hot-dip galvanized PEINER High Strength bolts and washers,
when placing washers it should be made sure that the beveled surface of a washer properly adjoins respectively a bolt head or a nut,
nuts should be placed with a marked front surface outside and manually run down the thread on their entire height,
in order to obtain the required pretension level Fv, the tools used for tightening should make it possible to precisely adjust the tightening torque or accurately read its value,
tightening tools should be controlled according to regulations,
pre-tensioning may be achieved by a controlled tightening torque method, torque impulse method or angle controlled tightening ('turn-of-nut') method - with adherence to principles included in adequate standards related to technical requirements for construction and inspection of steel structures - and with compliance to the values shown in the following table:
Required compression force Fv with impulse method (use of an impact wrench)
Required initial tightening torque Mv with turn-of-nut method
hot-dip galvanized nut lubricated with MoS2
black nut lightly lubricated with oil
[mm]
[kN]
[Nm]
[kN]
[Nm]
M12
50
100
120
60
10
M16
100
250
350
110
50
M20
160
450
600
175
50
M22
190
650
900
210
100
M24
220
800
1100
240
100
M27
290
1250
1650
320
200
M30
350
1650
2200
390
200
M36
510
2800
3800
560
200
Caution: Tightening torque values for nuts lubricated with MoS2 are different to those for nuts lightly lubricated with oil.
All components of the fastener assembly should originate from the same manufacturer.
Additional lubrication of bolts, nuts and washers changes the clamping force and causes installation failures.
Only in case where the required tightening method involves turning the head of a galvanized HV bolt, the molybdenum disulphide lubricant should be applied on a washer under the bolt head.
