Author Topic: bolt / nut threads  (Read 416 times)

Online RDfella

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Re: bolt / nut threads
« Reply #30 on: 16.09. 2019 19:49 »
I hate metric. I can’t visualise a metric size and have to convert to imperial to get an idea of the size. 32mm means nothing to me until I recall it’s close to 1 ¼”. Same with 25mm and 100mm. Look at plywood: used to be 8’ x 4’. Now it’s a metric size. 3m x 2m perhaps? No, it’s a conversion of 8’ x 4’ (2440mm x 1200mm). And the thickness mirrors the original imperial sizes.
Any mistakes I make when working in wood or steel are invariably when using metric. My favourite mistake is to cut a piece of wood at, say, 1.2m. Out comes the tape – one metre, plus two, cut …. oh dear, that was 1.02 not 1.20.
And the bolt sizes are a nightmare, with up to four different pitches per diameter. The French seem to follow close to imperial sizes on their vehicles with regard to spanner sizes (eg 13mm, 16mm etc) but the Japanese seem to love smaller sizes (10mm, 12mm)
Not forgetting the crafty and unnecessary odd sizes used, presumably to force DIY’ers to go to the dealer. 18mm is a favourite (I use a whit spanner for that) and other sizes that don’t appear in a normal set of spanners or sockets, eg 15mm. There’s another oddball size where 15/16”AF seems to fit quite well.
Let’s go back to imperial!. Personally, I preferred the Whit and BSF threads to UNC / UNF and definitely when compared with metric. I agree though that the spanner sizes for Whit were a bit odd and often the bolt head was bigger than seemed necessary.
And I’ve not the slightest idea what I weigh in kilos (all I know is that 1,000kg is roughly a ton) and I happen to weigh 16 ½ St.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Online Triton Thrasher

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Re: bolt / nut threads
« Reply #31 on: 16.09. 2019 19:51 »
Have you noticed that in a metric world whenever a new baby is announced, the weight is still given in pounds and ounces.

Babies haven’t had time to learn all that dekagram/nanolitre nonsense

Offline Gerry

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Re: bolt / nut threads
« Reply #32 on: 26.09. 2019 07:46 »
What about Pascals and Kilopascals and all that sh*t AAAAGGGHHHHHH. I now have a conversion table in the shed. When the metric system fist appeared did anyone notice that all new tape measures only had mm and Meters? That was until the huge huw and cry from the public that they weren't able to measure anything and they soon had tapes measuring in both inches and mm. lol When I was a diver I used to get my tanks filled with silly numbers until I managed to convert to 3000Lbs
Cheers Gerry

Online RDfella

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Re: bolt / nut threads
« Reply #33 on: 26.09. 2019 11:53 »
When metric first arrived, I was in the wholesalers one day getting a coil of copper pipe. Roll of 5/16 copper pipe please said I. Assistsnt - 'sorry, it's all metric now. You'll have to take 8mm. Ok said I, and what length are the coils now then? Twenty five feet mate.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.