SeymourDumore
Diamond
- Joined
- Aug 2, 2005
- Location
- CT
Guys, kinda stupid question here, but do need some help.
I'm getting ready to make some NPT threads in Inco 625 on a lathe, and I need to get them to specification not only in pitch dia and depth, but the min diameter bore dims as well.
Spent the last hour looking through the Machinist handbook and trying to decipher even the fine print stuff, but am yet to figure out how to calculate the bore diameter for a 3/4-14 Internal NPT thread.
I have the pitch diameters at the beginning of the thread, the pitch dia at the nominal length of the part, the taper angle ( 1 over 16 ), the nominal length, minimum OAL length ( wrench makeup ) and even the truncation allowances.
What I can't friggin' find is the minor diameter at any point of the thread!!!
I do have one number, which is .9105 dia, and is defined as: Basic Minor Diameter at small end of pipe.
Now, just what the hell does that mean? Is it the minor dia on the pipe's external thread, or the minor diameter on the internal thread?
A 3/4" pipe's nominal OD is 1.05", but without knowing the OAL length of the thread I can't figure out what this number mean.
Can someone kick me in the ass and point in the right direction please!
I'm getting ready to make some NPT threads in Inco 625 on a lathe, and I need to get them to specification not only in pitch dia and depth, but the min diameter bore dims as well.
Spent the last hour looking through the Machinist handbook and trying to decipher even the fine print stuff, but am yet to figure out how to calculate the bore diameter for a 3/4-14 Internal NPT thread.
I have the pitch diameters at the beginning of the thread, the pitch dia at the nominal length of the part, the taper angle ( 1 over 16 ), the nominal length, minimum OAL length ( wrench makeup ) and even the truncation allowances.
What I can't friggin' find is the minor diameter at any point of the thread!!!
I do have one number, which is .9105 dia, and is defined as: Basic Minor Diameter at small end of pipe.
Now, just what the hell does that mean? Is it the minor dia on the pipe's external thread, or the minor diameter on the internal thread?
A 3/4" pipe's nominal OD is 1.05", but without knowing the OAL length of the thread I can't figure out what this number mean.
Can someone kick me in the ass and point in the right direction please!