Nord-Lock X-series washers: Torque guidelines
The figures are based on tests with calibrated torque transmitters and load cells performed in our laboratory. Thread friction coefficients have theoretical values but are verified through testing. Under head friction coefficients have been established by tests. The below values are to be considered as recommended nominal values to maximize the preload achieved in joints secured with Nord-Lock X-series washers.
Should you require torque guidelines for other bolt grades, sizes or materials, we will be able to support you. Please email firstname.lastname@example.org or go to Contact us to find your local Nord-Lock office or authorized distributor.
Cu/C paste* = Copper/graphite paste (Molykote® 1000)
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = thread friction coefficient
μh = under head friction coefficient
1 N = 0,225 lb
1 Nm = 0,738 ft-lb