BS ISO 4580:2021 pdf download – Aerospace — Drives, internal, TORX® PARALOBE® driver bit — Geometrical definition, gaging and technical requirements
This document specifies basic dimensions, characteristics and engineering requirements for TORX ® PARALOBE ® 1) driver bits used with aerospace fasteners.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4579, Aerospace — Drives, internal, TORX® PARALOBE® drive — Geometrical definition, gaging and technical requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
driver bit
tool to induce a torque into a fastener’s recess (3.2)
geometry in a fastener that allows attaching a tool in order to induce a torque to enable tightening and untightening of a fastener
4 Basic driver bit configuration
4.1 General
The basic driver bit configuration shall be in accordance with Figure 1. Driver bits according to this document shall be used in conjunction with fasteners having an internal TORX ® PARALOBE ® drive according to ISO 4579.
.3 Torque wrench/torsion machine
Hand torque wrench shall conform to applicable requirements.
Torsion machines or other power tools shall conform to applicable requirements.
7 Driver bit torque test procedure
The minimum driver bit torque values are listed in Table 1 and Table 2 when tested in accordance with the procedure below. These values should not be mistaken as assembly torque values nor fastener recess torque.
a) Set the torque test fixture configuration depth P for correct drive size as listed in Table 5.
b) Place driver bit in a suitable torque test apparatus.
c) Mate the driver bit within the configuration of the torque test fixture, ensuring that the bit is free to move in or out of the configuration but that the bit axis is constrained within 1° of angular alignment with the torque test fixture configuration axis.
d) Apply an end load as specified in the fastener standard or other applicable document. The total end load shall be effective at bit/torque test fixture configuration juncture.
e) With the bit mated to the torque test fixture configuration and the end load applied (but no torque applied), zero the torque measuring device.
f) Apply the torque slowly in the installation direction at a smooth, continuous rate until driver bit torsional fracture occurs.
g) Record the applied torque and mode of failure.BS ISO 4580 pdf download.