This standard specifies the requirements for high performance through hardened and carbon restored thread rolling screws with induction hardened points which have performance capabilities beyond those normally expected of other types of tapping screws. The standard relates to screws with the standard 60 degree thread form, ranging from sizes M6 to M12 and for use in applications where fastener toughness is a prime consideration.



As partial or complete decarburization of the thread of thread forming screws seriously impairs the thread rolling properties of the screw, this condition is not permitted. Decarburization as permitted by ISO 898/1 is replaced in this standard by a requirement for carbon restoration as detailed in Clause 3.2.



Fasteners produced to this standard possess mechanical properties in line with ISO 898/1 property class 10.9 (010) except surface hardness.



Clause 3.4 defines thread forming capability in steel up to a hardness of 150 HV and thickness equal to the screw diameter. The parameters of material hardness and thread engagement may be varied by analysis of joint requirements and it is therefore recommended that the specific application be investigated to determine joint criteria.



NOTE: Lubrication approved by Ford is permitted on parts to which this specification is applied unless otherwise specified.