5"-4un Internal Thread Specifications

[SheldonB]

Hi . . anyone know of a site to download free or purchased thread specifications on large internal unified screw threads. 5"dia-4un
What I've seen go up to 4" dia only.

[plonky44]

work it out
.64 devided by TPI gives the depth

IE 4pi un
.64 Dev 4tpi=.160 depth per side.................
if it 4 TPI it is the same depth of thread as the 4inch UNC anyway]

5 inch minus .160-.160=4.680 root dia aprrox........


regards plonky

[Pressfit]

Yeah you don't really need charts but they do make things faster if you have them.

Just for added info. 100% thread contact you would have used .866, but I have never made 100% threads. I have done 95% in Aerospace once.

Plonky's reply is based on 3/4 full thread which is pretty much standard for thread contact.

(for your 'GO' male gage)
Nominal Pitch Dia. will be 4.8376 inches... ('GO' for all classes)

Best wire size is .14432

Measurement over wires 5.0541