Thread.xls... What is the Thread Runouts column

[karthur1]

Can someone explain what the "Thread Runouts" column controls in the Thread.xls?  I looked in the help and the knowledge base, but that didn't help at all.

I did find a knowledge base article that was very in-depth, but it has not been updated for 2017.

Thanks,

Kirk

[blair]

It's the portion at the end of a threaded shank which is not cut or roll threaded to full depth but which provides a transition between full depth threads and the fastener shank or bolt head.

[karthur1]

Blair,

Your explanation seems correct.  That's what most of us call incomplete threads.

I just noticed that when I create a tapped hole, the value for the hole depth is taken from the "Thread Runout" column.

Wish they would have just name the column "Tap Depth"... guess they like confusing us.

Thanks,

Kirk

[karthur1 · Accepted solution]

Just to clarify, the "Thread Runout" column is the distance the tap drill extends beyond the tap depth.  Its not actually the tap drill depth.  The tap drill depth is the sum of tap depth + thread runout.

Kirk

[Marco_Caprez]

Hi,

Is there a formula for the "Thread Runout" values?

Or do I have to look it up in the book?

I've been told, that "Thread Depth" is double the size (Col A in the Excel sheet) (e.g. for size 10 = 20).

Is this correct?

Thanks,

Marco

[karthur1]

The thread runout value is the depth the tap drill extends beyond the threaded portion of the hole. It is usually based off the thread pitch and not the nominal size. In the original Thread.xls file, the thread runout formula is 5/TPI.  

The thread depth is the depth of complete threads in the hole. Using the 2*Nominal Diameter is a common formula (for steel). This may have to be increased if a steel bolt is used in softer material, i.e. aluminum or brass, in order to prevent stripping the threads when the bolt joint is loaded.

Hope that helps,

Kirk

[Marco_Caprez]

Hi Kirk,

Thanks! That helps me a lot. 

Cheers, Marco