Cutting Threads Using a Die

[TonyL]

Hi Folks:

From all of readings, it appears that the thread diameter less the pitch is the starting dimension of the rod to be threaded (i.e, M10 less .75 = 9.25MM starting rod dimension.)

I have see several videos where the demonstrators start with the same dimensions as the die: a M10 die used on top of a 10mm rod). I guess this will simply results in deeper threads?

How to you go about this?

Thank you.

 

[bmachin]

Tony,

Thread diameter less the pitch will get you a rod that the die will just slide on to. Thread diameter less the pitch is the hole size for a tapped hole.

For threading male thread, start with the nominal diameter or a couple of thousandths under.

Bill

 

[magpens]

Tony,

As Bill said, when you are threading a rod (external threads) with a die, you do NOT subtract anything (except perhaps a couple of thou, possibly).

If you want M10 threads on the outside of a rod, you leave the rod at 10mm , and apply your die to that. . Die size M10 x 0.75

 

[magpens]

Tony,

It is only when you are cutting internal threads that you do the substraction to determine what drill size to drill the starting hole for the female threads.

Example: M10 x 0.75 female threads ... Drill a hole 10mm - 0.75mm = 9.25mm and apply your TAP to that. . Tap size M10 x 0.75

 

[TonyL]

Thank you for clarifying!