Determining diameter of machined shaft prior to threading. 1

[Mustang5L5]

I'm designing something simple where i need to create an internal and external 9/16-18 threading.

I know i need to drill the bore to 0.5156" prior to tapping

What diameter do i need to machine the shaft to prior to running the 9/16-18 die down it to create the thread?

Thanks

 

[MintJulep]

9/16

 

[CorBlimeyLimey]

http://www.efunda.com/DesignStandards/screws/unified.cfm?start=64&finish=147

 

[tbuelna]

For a .5625-18 UNF-3A thread, the major diameter limits are .5625/.5538.

For a .5625-18 UNF-2A thread, the major diameter limits are .5611/.5524.

Good luck.

Terry

 

[Mustang5L5]

Thank you all

 

[KENAT]

For UN threads the relevant spec is ASME B1.1

If you don't want to get that and are willing to accept free information from the internet try:

http://www.boltplanet.com/default.asp

Make the relevant selections (you don't have to put values in for the stress calcs) and 'calculate now' A pop up will appear, at the bottom of this is the diameter info for both male & female.

KENAT, probably the least qualified checker you'll ever meet...

 

[KENAT]

Oops, ASME B1.1 is relevant in the US the UK has it's own equivalent spec (I guess Canada does too but I don't know for sure)

KENAT, probably the least qualified checker you'll ever meet...

 

[strokersix]

Unless this is a critical application, shoot for the low side for the major diameter. A threading die sometimes has a tough time (galling, excess chip volume) if the diameter is nominal and/or if the threading die is in less than perfect condition. A good method to use is single point threading in the lathe to get close, then run the die on to finish size.