BSW (British Standard Whitworth)

[colly]

Where:

P = Pitch = 1/Number of threads per inch (tpi)
h = Angular Depth = 0.960491 x P
D = Depth of Rounding = 0.073917 x P
h/6 = Shortening = 0.160083 x P
d = Actual Depth = 0.640327 x P
r = Radius at the Crest & Root = 0.137329 x P
C = Core diameter = Major Diameter - 1.280654 x P
Effective or Pitch Diameter = Major Diameter - .640327 x P


It's not new I know but is an old favourite.

 

[threebikesmcginty]

Nice thread!

 

[colly]

Very good, but you have stated that the:
Thread Angle is 55°
Flank angle is 27°30'

Further, I don't quite agree with your figures.

Shortening at root and crest should read 0.1600819 x p

and

Depth of thread should read 0.6403274 x p
Depth of rounding =0.0739176 x p

I'm not sure I agree with your figures but if you are correct it would certainly put a new twist on things.

 

[colly]

British Association Thread

Thread Angle = 47°30'
Trianagular Height H = 1.1363365 x p
Shortening at Crest and Root S = 0.2681683 x p

I could go on, but it's club training tonight and I'm running late!!

I see your reasoning but I was talking the daddy of them all................BSW(British Standard Whitworth)

 

[atbman]

British Association Thread

Thread Angle = 47°30'
Trianagular Height H = 1.1363365 x p
Shortening at Crest and Root S = 0.2681683 x p

I could go on, but it's club training tonight and I'm running late!!

Typical - he's just bolted.

 

[rich p]

Nut screws washers and bolts

 

[very-near]

I'm an engineer and I think this is nuts

 

[colly]

I'm an engineer and I think this is nuts

Torque about rude !!!

 

[Hover Fly]

Would you like Lowenherz Thread or German Buttress Thread? Tomorrow!

Echols please.

 

[slowmotion]

I'm an engineer and I think this is nuts

Washer your mouth out.

 

[Chromatic]

Spooky, we've just bought a 6BA tap at work then this starts.

 

[alecstilleyedye]

i think this tread will just die…

 

[Saddle bum]

I am a bit if a thread anorak.

Versions of the Lee-Enfield rifle up to 1930 had a unique thread system inherited form the Birmingham gun trade. With another nerd, I have been studying the system and acquiring data for over 5 years now. Fascinating stuff, but guaranteed to send a non-believer to sleep with seconds.

Now that we have digital lathes, we can reproduce screws, which up to recently could only be made in small quantities by "knife and fork" methods.

 

[Aperitif]

I thought British Standard Whitworth was the normal size of dried fruit.

As usual, I didn't really - my Dad was an engineer and I 'inherited' (along with his wealth ) all sorts of pitch gauges, taps dies and whatnots + some oily pocketbooks impregnated in swarf and machine oil. It always used to fascinate me visiting his works on a Saturday morning (not least because I could get a cup of oxtail soup from the vending machine..."when soup was soup" etc) watching the milky fluid dribbling over the metal. Not forgetting the statutory pump of Swarfega - to identify me by smell as a young engineer.

 

[swee'pea99]

Whitworth....that's currants isn't it?