1/4-18 thread machine screw?

[Patches]

Looked on British Tools and Fasteners web site, thought it might be Whitworth or some other odd ball; they list their NPT 1/4"-18 tpi tap as being just that (1/4" diameter x 18 tpi). Catalog #5915 ???

 

[LD1]

Looked on British Tools and Fasteners web site, thought it might be Whitworth or some other odd ball; they list their NPT 1/4"-18 tpi tap as being just that (1/4" diameter x 18 tpi). Catalog #5915 ???

NPT 1/4" usually isnt even close to the same as bolt sizes. Did they happen to mention what drill size to use with that tap??

 

[Soundguy]

i agree.. you are getting near 3/8 with that npt pipe stuff..

 

[Midniteoyl]

Still say its a #14

 

[LD1]

Still say its a #14

All the #14's I have been seeing are 14TPI, not 18...

Correct diameter though...

 

[Midniteoyl]

All the #14's I have been seeing are 14TPI, not 18...

Correct diameter though...

True, but a Type B has finer threads than standard..

In any case, its a self forming thread and would work..

 

[LD1]

Even all of the type B's I seen were 14 TPI

 

[bd53bz2]

Would these windows be made in England? In the 50's there were a lot of british whitworth sizes out there. I had a couple of BSA's and a 1956 English Ford car. Matching was a pain......

 

[Zebrafive]

It's almost as if someone set up a screw machine wrong. Had 1/4" stock and 18 thread per inch cutters just adjusted them until they made threads?????
I've been watching this to see if the mystery is solved.

 

[SPYDERLK]

Strange alright. Could always buy lo grade 1/4-20 and give em a stretch

 

[LD1]

It's almost as if someone set up a screw machine wrong. Had 1/4" stock and 18 thread per inch cutters just adjusted them until they made threads?????
I've been watching this to see if the mystery is solved.

Kinda what I was thinking at first as well. Someone made some screws and did it wrong.

But...How did they tap the holes???

Mystery indeed

 

[Baby Grand]

Strange alright. Could always buy lo grade 1/4-20 and give em a stretch

That would "yield" you a 1/4-18!

 

[Soundguy]

not solved yet. i've sugested going 5/16-18 with a tap. it's the least invasive i think.

 

[SPYDERLK]

That would "yield" you a 1/4-18!

Well, :confused3: it would neck down a little - but close enuf. ... Actually, tapping to 1/4-20 should be plenty strong since the nut has greater thread root and thus its threads have inherent strength advantage over those on the bolt.

And heel be able to use either bolt. .

 

[Soundguy]

base material is aluminum.. have to take that into consideration as well.

 

[SPYDERLK]

A weaker nut metal would make some difference, but i didnt see it stated.
larry

 

[BukitCase]

At this point, I'd think one of THESE

Amazon.com: ramset

Would be lookin' pretty good.. :thumbsup: Steve

And yes, I'm kidding...