BS ISO 3353-2:2020

Aerospace. Lead and runout threads. Internal threads | Status: Current, Under review

What is ISO 3353‑2 about? ISO 3353 is a series of international standards on lead and runout threads that discusses the best procedures and specifications required for producing precise internal threads. ISO 3353‑2 is the second part of a series of documents on threads. ISO 3353‑2 specifies the lead and runout thread and undercut requirements for internal threads (blind tapped holes) for aerospace construction. ISO 3353‑2 is applicable whenever it is referenced in a definition document. Who is ISO 3353‑2 for? ISO 3353‑2 on internal threads is relevant to:

• Producer of internal threads
• Aerospace industry

Why should you use ISO 3353‑2? An internal thread is a thread on the inside of a member. The purpose of having threads is to join parts together while providing the opportunity to assemble and disassemble in the future versus a permanent situation. ISO 3353‑2 provides guidance on lead threads, runouts, undercuts of internal threads. As a user of ISO 3353‑2, you can be ensured of the lead and runout requirements for the internal thread. With obedience and compliance to ISO 3353‑2, you can efficiently produce high-quality internal thread. With ISO 3353‑2 you can be ensured that the threads consistently meet and exceed quality assurance targets. ISO 3353‑2 helps you to build consumer trust and confidence in the product. What’s changed since the last update? Together with BS ISO 3353‑1:2020, BS ISO 3353‑2:2020 supersedes BS 2A 231:1993, which is withdrawn. The main changes compared to the previous edition are as follows:

• Update of the term “lead threads”
• Editorially revised