combat wheel info

[Grant Bowker]

Originally Posted by Lynn Eades

BSF is the fine thread as opposed to whitworth which is the coarse British thread. both have a 55 degree included angle.with a rounded valley, and flat crests, while UNC/UNF have a 60 degee included angle, with flat valleys and flat crests. Thats how I understnd it anyway.
On thread forms. A turned thread from a lathe etc, will not be as strong as a roll formed thread (which the originals probably were) because the "grain' in the metal is cut by the lathe tool, whereas the grain in the roll formed thread follows the profile of the thread.
I think many "British Motor Lorries" have used 7/8 BSF threaded wheelstuds.(often 10 stud)

I think I'm starting to understand better, but I have seen references to BSW fine (usually with the word obsolete included) one web site is http://www.gewinde-normen.de/en/whit...ne-thread.html
I'm with you that I wouldn't choose a cut thread for maximum strength, but I might be willing to turn the head of a rolled bolt to make a mushroom or tapered head to weld to the rim. After all, the metallurgy can be altered by the act of welding the stud in place onto the rim so this might not cause a serious loss of strength. Also, the weld is as much to stop the bolt from turnig as it is to stop it pulling through the rim.

[Paul Singleton]

Dormer still lists a die in their catalogue.

http://www.dormertools.com/

It is on page 23 in the catalogue.

http://www.dormertools.com/sandvik/2...et/s003591.nsf


F350

BSF TPI e-Code
7/8 11 22.23 2“ 5/8 F3507/8X2

● Adjustable Dies ●

Paul

[Corey Myronuk]

what Lynn was saying about rolled threads is correct.But would the high speed ball milling of the cnc making a round bottom thread root create the same kind of stress riser as a lathe cut thread?They should also be post forming heat treated too right?hmm....

[rupert condick]

lwdparts have some studs nos, if they are the right ones,
i would not worry about the welding in as the original metal was probably very poor anyway compared to today, i would use allen bolts if i was really worried. and fit a collar on the end, and weld that in.
regs
rupert

[Grant Bowker]

Originally Posted by DUUANE

what Lynn was saying about rolled threads is correct.But would the high speed ball milling of the cnc making a round bottom thread root create the same kind of stress riser as a lathe cut thread?They should also be post forming heat treated too right?hmm....

The issue isn't just the shape of the thread root but the rolling process forms the grain stucture of the metal as opposed to interrupting it as a cut thread does.
As comment, they did experiment with press in studs on the CMP wheels and found that the wheel material was too thin to properly hold the studs (hard to believe when we see how heavy the CMP wheels are compared to modern, but they ran tests and had failures...) so they found they had to keep the welded in studs.