FORD WE955

Description / Abstract: FORD WE955, 2018 Edition, May 29, 2018 - MECHANICAL AND PERFORMANCE PROPERTIES OF HEXAGON FLANGED NUTS WITH SPECIFIED PROPERTY CLASSES INCLUDING PREVAILING TORQUE & CONICAL WASHER ASSEMBLIES

This standard specifies the mechanical and performance requirements for free running and prevailing torquetype steel hexagon flanged nut and hexagon flanged nut and washer assemblies. Prevailing torque feature includes all metal or non-metallic insert. This specification assumes nuts have the following:

a) Nominal diameters M5 to M24 inclusive.

b) Strength requirements of property classes 8 and 10, according to ISO 898-2.

c) Dimensions as specified in the Worldwide Fastener Standard or on Utility Part drawings.

d) Service temperature ranges:

1) -50 to + 300 °C for all metal nuts¹.

2) -50 to +120 °C for non-metallic insert nuts.

e) Coarse pitch threads

f) A coating containing integral lubrication properties.

g) Capability of being assembled on bolts with pilot points in accordance with WA 900.

h) Free running or prevailing torque

i) All metal prevailing torque feature by way of thread distortion, or Non-metallic prevailing torque feature utilizing an polyamide (PA) insert

¹For 120 to 300°C, consult finish service temperatures in WX 100. For applications with temperatures above 150°C, design validation should consider stress relaxation and reduction in yield strength.