Post by Harold_V » Fri Dec 26, 2008 3:36 pm

Not so fast with the corrections. There are no "one size fits all" where threads are concerned.

For some reason, there appears to be a back aswards approach to this issue. Thread sizes are based on the fraction involved. There is no need to do any calculations unless you are dealing with a bastard thread. It makes no sense to complicate what is a very simple issue.

The flat of a thread is governed by the specifications of the American standard and unified thread series. For class 2 threads, there is a clearance allowance that dictates that the major will be on the minus side, and there is a tolerance that controls that diameter. There is no allowance for class 3 threads, so the maximum major diameter is the nominal size.

For an example, a ¼"-20 2A thread has a theoretical major diameter of .250", with an allowance of .0011", making the top tolerance of the thread major diameter .2489". The major diameter then has a tolerance that permits the diameter to be as small as .2408". The tolerance for the major diameter changes with the class of thread, so charts should be referenced when threads must meet specific requirements. A class 1 thread has a very broad tolerance as compared to a class 3.

There are no more or fewer charts for class A threads than there are for class B threads. All threads are equally controlled, with specifications published for all features that are crucial.

Harold

Different Types of Thread Rod

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Thread Rod: A length of metal rod that is a thread from end to end is called a threaded rod. It is also known as Thread Rod or Thread Stud. There are many kinds of lengths and materials available for thread rods. These thread rods are usually used to connect materials. These connectors are commonly used to join wood and metal pieces but can also be used in the construction and plumbing industries to provide stability.

The features of aluminum thread rods are mostly specialized for their durability and less weight. Even brass rods have features like corrosion resistivity and the ability to function in different temperatures. These materials are not used only for making thread rods. Rods made from copper, steel, bronze, and titanium are also available.

How is Thread Rod Made?

Thread rods are made from a round bar at a specified grade and diameter. Thread rolling machines will typically mass-produce standard diameter and grade thread rods. These processes involve passing the thread bar through two hardened steel rollers to imprint the thread onto the round bar. These rollers are set at a specific distance apart and rotate perpendicular to the direction the thread bar is being passed through them, and the extremely high pressure the rolls apply mold the round bar on the threaded rod. The Thread Rod is sawed to size, and the edges are beveled to provide a smooth, finished surface.

Non-Standard Thread Rod is usually made via a cutting process. The round bar is cut to a slightly longer than desired length and passed through a machine that cuts the thread from the surface as it forced along. The Thread Rod is most commonly made from stainless steel and carbon steel, depending on the final application.

Different Types of Thread Rod

Fully Thread Rod: Fully Thread Rods are metric bolts from top to bottom. These rods with this design may be more suitable for situations requiring strong grips over strong shears. These thread rods are frequently used in automobile body panel alignment and other applications where loosening resistance is required. Several applications require loosening resistance, include automobile body panel alignment.

Partially Thread Rod: These rods feature partial thread that begins at the rod length’s bottom. The rod length where there is no thread is called the grip length. The grip length will vary depending on the thread rod’s intended purpose.

Benefit of Thread Rods

The Thread Rods are mainly used in professional construction, conservation, repair, processing, and other applications. The following are some assignments in which thread rod use:

• Electrical installation
• Plant conservation
• Medical machinery
• Formation
• Automotive assembly and repair
• Agricultural uses
• Marine applications and engineering
• Manufacturing, processing, and production