ISO 2702:2011 pdf download.Heat-treated steel tapping screws 一Mechanical properties.
4.2.1 Thread-formIng capability
Tapping screws shall form a mating thread without deforming their own thread when driven into a test plate, in
accordance with 6.21.
4.2.2 Torsional strength
Tapping screws shall have a torsional strength such that the torque necessary to cause failure, when tested in accordance with 6.22. shall equal or exceed the rrwnlmum torque values given In Table 3 for the applicable screw threads
5 Acceptance
For routine acceptance tests, the drive test, torsional test and core hardness test may be used, but for referee purposes all requirements specified in this International Standard shall be satisfied.
6 Test methods
6.1 Test methods for the metallurgical requirements
Tapping screws shall form a mating thread without deforming their own thread when driven into a test plate, in
accordance with 6.21.
4.2.2 Torsional strength
Tapping screws shall have a torsional strength such that the torque necessary to cause failure, when tested in accordance with 6.22. shall equal or exceed the rrwnlmum torque values given In Table 3 for the applicable screw threads
5 Acceptance
For routine acceptance tests, the drive test, torsional test and core hardness test may be used, but for referee purposes all requirements specified in this International Standard shall be satisfied.
6 Test methods
6.1 Test methods for the metallurgical requirements
6.1.1 Surface hardness test
The Vickers hardness test shall be carned out In accordance with ISO 6507-1.
The impression of the pyramid shall be made on a flat face, preferably on the screw head.
6.1.2 Case depth — MicroscopIc test
Case depth shall be measured at the thread flank mid-point between crest and root or. in the case of smaller tapping screws up to ST3.9. in the root of the thread.
For referee purposes, a micro hardness plot shall be made using a Vickers indenter and a 300 g load on the thread profile of a propeily prepared metallograpilic specimen. The case depth shall be the point at which the hardness recorded is 30 HV above the actual core hardness.
6.1.3 Core hardness test
The Vickers hardness test shall be carned out In accordance with ISO 6507-1.
The impression of the pyramid shall be made on a flat face, preferably on the screw head.
6.1.2 Case depth — MicroscopIc test
Case depth shall be measured at the thread flank mid-point between crest and root or. in the case of smaller tapping screws up to ST3.9. in the root of the thread.
For referee purposes, a micro hardness plot shall be made using a Vickers indenter and a 300 g load on the thread profile of a propeily prepared metallograpilic specimen. The case depth shall be the point at which the hardness recorded is 30 HV above the actual core hardness.
6.1.3 Core hardness test
The Vickers core hardness test shall be carned out In accordance with ISO 6507-1 at the mid-radius of a transverse section through the screw taken at a distance sufficiently behind the point of the screw to be through the full minor diameter.
