Basic Specifications

◎ External and internal diameters of British Standard screw threads must meet the requirement of ASME B1.1:2003.

◎ External threads of counterparts must meet the tolerance of 6g ring gauge. Internal threads of counterparts must meet the tolerance of 6H bolt gauge. 

◎ For internal threaded counterpart (i.e. nuts), chamfer processing is necessary and it should not have any sharp burr.

◎Coating length should be at least 4 pitches long, and the coating design should be based on the actual locking position on the counterpart as well as common application. 

◎ The design of self-locking torque is based on IFI specifications. Please consult us in advance for any special requirement.

Self-Locking Torque Inspection Specification

IFI stands for International Industrial Fasteners Institute, and IFI-524/ IFI-124 are the only globally recognized self-locking torque inspection specification for non-metallic self-locking material. IFI specifications are also the fundamental principles of self-locking specifications for other industries.