What is a 3A class thread?
What is a 3A class thread? Class 3 threads are tight tolerance threads that have no allowance and have very tight tolerances. Class 3 threads are often specified for tight tolerance fastener applications in critical use situations where safety and strength are a primary concern, such as the aerospace industry.
Why use class 3 threads?
Classes 2A and 2B are the most common thread classes in use, offering a balance of ease of manufacture, cost, and performance. Classes 3A and 3B are best suited where close tolerances, safety, and strength are required, and thus are frequently specified for socket cap and socket set screws.
What is A and B in threads?
There are (3) established Classes of Thread, designated in the unified series by adding: A for Screws and B for Nuts (or other intenal threads) to show definite limits and tolerances. Class 1B Thread. Is wherea 1A screw can run in readily for quick and easy assembly. The hole is classified as 1B.
What does 3B mean in threads?
Class 3B is the tightest tolerance and used for close fit and high strength fastening applications where a close and snug fit are required.