Thread Limit is a standard notation system indicating a level of tolerance for the thread outside the basic thread size of the tap. The limits are identified by a letter "H" for inch or a "D" for metric, followed by a number.
The kernel parameter threads-max controls the maximum number of threads. This parameter is defined in the file /proc/sys/kernel/threads-max. Here, the output 63704 indicates that the kernel can execute a maximum of 63,704 threads.
A single CPU core can have up-to 2 threads per core. For example, if a CPU is dual core (i.e., 2 cores) it will have 4 threads. And if a CPU is Octal core (i.e., 8 core) it will have 16 threads and vice-versa.
Once the class of thread and part tolerance has been defined, an H limit is selected to produce a thread that is within the minimum and maximum limits for that class if fit. These limits are the same as the Go and Not Go thread plug gage dimensions.
6H - Tolerance of 6H for the Pitch Diameter. 4H - Tolerance of 4H for the Minor Diameter.
The number after the H or L, indicates the amount it is different than the basic pitch diameter. Each number after the H or L is equal to 0.0005, so an H3 or L3 is equal to 0.0005 x 3 or 0.0015.
Classes 2A-2B
Class 2A external threads have an allowance, Class 2B internal threads do not. Classes 2A and 2B, for most engineering applications, offer the optimum thread fit that balances fastener performance, manufacturing convenience and economy.
Thread tolerance 6H is the recommended tolerance for metric internal threads. Thread tolerance 6g is the recommended tolerance for metric external threads.
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.
A thread is a set of instructions or code for the execution of concurrent programming. A single server CPU core can have 2 threads. If a CPU has 8 cores with two threads per core, it will have 16 threads to perform tasks.
There are 4 to 10 threads per core on the GPU. GPU follows Data-parallelism and applies the same operation to multiple data items (single instruction, multiple data {SIMD}). GPU cards are primarily designed for fine-grained, data-parallel computation. The input data process the algorithm.
Although there isn't much memory overhead for each thread, there is overhead for the thread scheduler to manage them. If we only have 4 cores, only 4 threads can execute instructions simultaneously.
Each of these, aside from the usual feature limitations based on the market, also have limitations on processor counts and sockets. In the diagram above, we can see where it says Windows 10 Home is limited to 64 cores (threads), whereas Pro/Education versions go up to 128, and then Workstation/Enterprise to 256.
You can have many threads because a processor core can execute instructions on one thread for awhile, and then switch to another thread, executing some instructions there. This process occurs rapidly and continuously, making it appear that all threads are executing simultaneously.
G (supposedly from German/English “Gas”) are the cylindrical pipe threads with 55°apex angle used on originally inch based pipes. BSPP thread is often referred to as “G” threads, the two types of thread are the same parallel straight, the threads are measured in threads per inch. Therefore, BSPP is the same as G.
A fine thread geometry with a greater number of threads per inch will inherently have a shallow thread depth resulting in a larger minor diameter and greater root area. This allows for a fastener with larger stress area capable of being stronger in tension.
m8 means metric thread 8mm of ISO standard and 6H refers to tolerance of threaded hole (know more about it in ISO 2768) 2 0.
The square threads are not so strong as V-threads but they offer less frictional resistance to motion than Whitworth threads.
The V size is the common US measurement for twisted, multi-ply bonded nylon or polyester threads. Larger numbers indicate heavier threads. The T sizes represent the “Tex” measurement system, where the number equals the weight in grams of 1000 meters of thread. If 1,000 meters weighs 70 grams, it's a Tex 70 thread.
Class 1A is a loose commercial fit for easy assembly and disassembly. Class 2A is a medium fit. Class 3A is a tight fit used where a closed fit between mating parts is required.
The 3A/3B thread fit has no allowance and smaller tolerances than the class 2A/2B thread fit, resulting in a tighter fit.
Class 3B is the tightest tolerance and used for close fit and high strength fastening applications where a close and snug fit are required.
Classes 1A and 1B are infrequently used, but they do have their applications. They are ideally suited when quick assembly and disassembly are a key consideration in a design. Classes 2A and 2B are the most common thread classes in use, offering a balance of ease of manufacture, cost, and performance.