The thread lead angle calculator calculates the lead angle for a screw or bolt based on either the threads per inch, thread pitch, or lead. While English screws typically use the number of threads per inch, metric screws use pitch, which is the distance between two threads. Ultimately these are two ways of expressing equivalent information, we have a blog post outlining TPI and Pitch and one that covers the history of different screw threads.

Select the Method to enable the appropriate input boxes. Threads per Inch and Pitch require 'Pitch' and 'Number of Thread Starts' while Lead only needs the 'Lead' box

Screws can also have multiple starts, which allow them to screw in faster, that is to cover more distance per revolution, while retaining original thread pitch. This can be accounted for by either entering the number of thread starts, or directly calculating the Lead. Lead is the linear travel the nut makes per one screw revolution. For a single start thread, lead is equal to the pitch. For multiple start screws, the lead is the pitch multiplied by the number of starts.

Deep Drill is similar to Drill & Fill but, as the name suggests, there is no fill, just drills. However, these special Deep Drill machines go deeper into the profile and have a tighter spacing (5” on center, 5/8” drill bit, up to 18” depth).

Since the lead angle is unitless, the chosen units for dimensions don't matter as long as they are consistent. That is, if lead is given in mm, the diameter needs to be in mm as well. Likewise, both dimensions could be in inches, or anything else as long as they are the same.

Based on the results we’ve seen and the feedback we’ve received, we truly feel this is one of the best services offered to golf course Superintendents. Our clients usually become annual Deep Drillers because it just works so well.

Deep Drill not only alleviates and prevents subsurface sediment layers, it also dramatically improves gas exchange.  This process is done on greens constructed to USGA® specifications (sand-based greens with gravel layer)

This process punctures and churns sediment layers that have developed over many years at the soil/gravel ‘hanging water table interface.’ These sediment layers, although deep, create undesirable high moisture retention all the way to the playing surface. This condition usually results in soft surfaces and unhealthy turfgrass roots. As seen in the picture to the right, sometimes a small amount of pea gravel will be brought to the surface during the drilling process.  The process punctures and churns the top of the gravel layer where sediment accumulates.

The Lead Angle is the angle between the helix and its plane of rotation. In a screw, this is the angle the threads make relative to its rotation. One can imagine that as the thread pitch increases (finer threads, with closer spacing) each thread is closer to being vertical, and so the angle is less and less. Conversely, as threads get coarser each thread covers more length along the screw and so the angle increases