TIL car tyre sizes (eg, 225/55R17) manage to combine metric (225mm width), a percentage for an aspect ratio (55%), and imperial (17 inch diameter). I think that’s just marvellous. Well done everyone.
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Jon
in reply to Benjohn • • •Alex@rtnVFRmedia Suffolk UK
in reply to Jon • • •@oddhack they are across the whole of Europe, BSP threads and I think the plumbing for washing machines and dishwashers is the same (I'm unsure how/why this became a standard and not something metric as surely the British didn't export garden hoses to the entire continent?)
en.wikipedia.org/wiki/British_…
standard set of screw thread sizes used in pipe fittings
Contributors to Wikimedia projects (Wikimedia Foundation, Inc.)publius
in reply to Alex@rtnVFRmedia Suffolk UK • • •@vfrmedia @oddhack
Camera mounts are 1/4" × 20 threads per inch Whitworth thread, meaning they are incompatible with any bolts or nuts you can buy in any hardware store anywhere.
If the British didn't have a monopoly on hose bibbs, they certainly had a monopoly on the machines that made them.
stib
in reply to publius • • •Yeah, but they're the same diameter and TPI, only difference between them is the angle between the thread thread flanks in one is 55°, and the other is 60°. So unless you're building aeroplanes or bridges, UNC ≈ BSW. Normal hardware store 1/4" UNC will fit camera gear just fine, I use it on movie camera rigs at work all the time.
@vfrmedia @oddhack @benjohn
Nick Taylor
in reply to stib • • •Autoerotic Defenestration
in reply to Benjohn • • •button batteries are also named for their dimension, but they managed not to mix units unnecessarily:
CR2032: lithium, round, 20 mm diameter, 3.2 mm height, (220 mAh)
groff 🇺🇦
in reply to Benjohn • • •Did you know that ISO standards are based on myth and superstition?
ISO 724 - Metric Screw Threads, specifies threads from 1-12mm and 14-18mm, each in 1,2 or 3 different pitches. There are no 13mm threads, at all!
Nina Kalinina
in reply to groff 🇺🇦 • • •groff 🇺🇦
in reply to Nina Kalinina • • •@nina_kali_nina
Now you've done it.
American and Imperial, UNC and BSW, course threads have diameters and thread counts that match, they only differ in thread angle (UNC has a thread angle of 60° and BSW is 55°), so can be normally be interchanged in all but critical applications.
Except for one of the most common sizes, bloody ½", where BSW is 12 TPI and for some odd reason the Americans went with 13 TPI.
Perfect for ruining a simple job late on a Friday afternoon.