According to standard requirement, during assembly you should not use any additional lubrication apart from that originally supplied.
BS EN 14399 standard is leaving a clause, that additional lubrication should be used if it is subject to supplier recommendation.
Andrews Fasteners BS EN 14399 Assemblies are supplied to k-Class k0 and are offered pre-lubricated.
We are supplying lubricated parts of the assembly. Lubricated parts are used where due to surface coating, maximum tension needs to be controlled to prevent seizure.
On assemblies BS EN 14399 k-Class K1 and K2 additional lubrication would modify the values of km and invalidate the BS EN 14399-2 test results. In that situation, additional lubrication shall not be used.