Mechanical and Performance Requirements of Through Hardened and Carbon Restored Thread Rolling Screws for Use in Aluminum Applications
|Publication Date:||20 July 2010|
This standard specifies the requirements for high performance through hardened and carbon restored TAPTITE 2000® "SP"™ thread rolling screws which have performance capabilities beyond those normally expected of other types of tapping screws. The standard relates to screws with Radius Profile™ screw thread form, ranging from sizes M3 to M14 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 8.8 except surface hardness.
Clause 3.4 defines thread forming capability in aluminum up to a hardness of 150 HV and thickness equal to 2x the nominal 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.