Thread: US vs British (and Australian?) woodworking terminologies

So how about the Miners Inch? Different 'standards' in NZ, Canada and various states in the USA.

Originally Posted by elanjacobs

At least we had the good sense to ditch the board/super foot. That just does my head in.

Just to steer this back to the OP a bit....

Elan, don't close your mind to the super foot (or board foot, another terminology difference)! It is an extremely useful measure if you work in Imperial units. What you have to realise is that it's a volume measurement, like a litre. Because it was defined as 12 x 12 x 1 inches (the 'proper' name is "superficial foot"), & so many boards used in building & cabinetmaking were (nominally) an inch thick, it could often make it very easy to calculate pretty closely in your head, how much stock you'd need to pull out for a job. I lament the loss of it, a litre just doesn't have a particular shape in my mind, and although theoretically it could serve the same purpose (if our lumber sizes were genuinely tied to metric) it just never came across when we switched...

And the old chestnut about 2 x 4s or 4 x 2s being 1/4" under, well blame wood: they were cut at 2 inches by four inches at the mill, but different shrinkage rates for different woods means less to start with when dressing the high shrinkage species, so folks sensibly settled on a standard 1/4 under nominal to be sure you'd get boards of any species squared...

Cheers,

Originally Posted by elanjacobs

How so?

Originally Posted by GraemeCook

Crocy doesn't have any metric taps or dies ?

Originally Posted by elanjacobs

or a lathe that will cut metric pitches?

This has really got off course. Yes I do have metric taps and dies up to 12mm. I have 3 metal lathes, an imperial Nuttall and 2 metric Emco's, one is belt drive the second is a full gearbox model.
Why Is BSW easier to cut? The Nuttall is so easy to knock out of gear cutting a thread up to a shoulder. But the metric ones I have to guess how much it will run on when I switch off the motor hoping it doesn't hit the shoulder so that I can wind the tool out to reverse the sucker.
As I said, BSW, use the thread chasing dial to drop it into gear on the right division and Bob's your uncle.
Have a lovely night everyone.
Rgds,
Crocy

Originally Posted by Old Croc

But the metric ones I have to guess how much it will run on when I switch off the motor hoping it doesn't hit the shoulder so that I can wind the tool out to reverse the sucker.

Mount the tool upside down, run the lathe in reverse and start at the shoulder with the tool in position. The tool can then run off the end with no problems.

Originally Posted by Bohdan

Mount the tool upside down, run the lathe in reverse and start at the shoulder with the tool in position. The tool can then run off the end with no problems.

Yep tried that, followed Joe Pie's video with mixed results. I only cut 2 or 3 metric threads a year, everything else is Imperial.
Rgds,
Crocy.

An interesting thread is never 'Off-Coarse'....

Originally Posted by IanW

....Elan, don't close your mind to the super foot .....

I lament the loss of it, a litre just doesn't have a particular shape in my mind.....

The mind boggles, Ian.

Timber yard scenario: "Could I have 100 litres of 4x2's, please."

Hi,
I must admit I find it hard to visualize how many planks and the cost when the price is only put up in cubic meters.
Regards

Same here. I feel as thick as two short planks!

Originally Posted by GraemeCook

......Timber yard scenario: "Could I have 100 litres of 4x2's, please." ....

Well Graeme, that's pretty much what we did back in the day, only we asked for X super (or X Bf if in that other part of the world). As I said, a super-foot is a volume, not a linear measurement. Pricing was done in SF then, just as it is in cubic metres now.

But I rest my case on this point: when pulling out stock for a job, one usually ends up with mixed widths, say 4", 6" 12". It's no coincidence that these are all multiples of 12, so it was very easy to calculate in your head, how many SF you had. Not only does it help you to pull out the right amount for the job, when you fronted up to the cash register & they worked out what you'd got in SF (as they did), if your tally & theirs disagreed wildly, you could have a useful discussion. Nowadays, when the man/woman calculates the damages on the pile of different sizes/widths I've gt, & comes up with a column of fractions of cubic metres to 4 or 5 decimal places, I haven't the foggiest idea if they are even in the ball-park!

I just think "strewth, wood is getting costly", pay my money, & drag it home...
Cheers,

Originally Posted by GraemeCook

Damian

A lot of gnomes in Swtizerland make a lot of watches every year, and those watches contain heaps of itsy bitsy little screws. None have Whitworth threads. Could you kindly explain?

Watches aren't a high strength application. They do endure vibration but watchmakers have specific means to stop threads loosening.

Have any of you ever wondered why we have coarse and fine threads ? It is for better holding in different materials and better vibration resistance where economics prohibit anti vibration measures beyond tightening the fastener. Fasteners are a whole science unto themselves.

Whitworth has fewer diameters so you know at a glance what size you are dealing with. They were designed in days before economics saw engineers specifying 20 different diameters to save pennies. The spanners are named by the shank diameter not the head diameter.

The various british threads were designed by engineers according to need. Metric threads are an inferior rounding off to the nearest 10 base.

Incidentally in case anyone cares I used to work at this place many eons ago:

Size matters: inside Australia’s National Measurement Institute - Australian Geographic

Originally Posted by Old Croc

This has really got off course. Yes I do have metric taps and dies up to 12mm. I have 3 metal lathes, an imperial Nuttall and 2 metric Emco's, one is belt drive the second is a full gearbox model.
Why Is BSW easier to cut? The Nuttall is so easy to knock out of gear cutting a thread up to a shoulder. But the metric ones I have to guess how much it will run on when I switch off the motor hoping it doesn't hit the shoulder so that I can wind the tool out to reverse the sucker.
As I said, BSW, use the thread chasing dial to drop it into gear on the right division and Bob's your uncle.
Have a lovely night everyone.
Rgds,
Crocy

Exactly what I was going to say.

Originally Posted by Old Croc

Why Is BSW easier to cut? The Nuttall is so easy to knock out of gear cutting a thread up to a shoulder. But the metric ones I have to guess how much it will run on when I switch off the motor hoping it doesn't hit the shoulder so that I can wind the tool out to reverse the sucker.
As I said, BSW, use the thread chasing dial to drop it into gear on the right division and Bob's your uncle.

So let me get this straight...BSW is easiest for you to cut with the equipment you have, therefore it's objectively the best thread?

Sorry, but that's just a ridiculous way to determine what is good and what is not.

Originally Posted by elanjacobs

So let me get this straight...BSW is easiest for you to cut with the equipment you have, therefore it's objectively the best thread?

Sorry, but that's just a ridiculous way to determine what is good and what is not.

I don't believe that's what I implied,
I am currently making a new 4 point steady for the wood lathe, all metric threads. Waiting on some female ratchet lever handles from Hong Kong.
I am currently rebuilding a 1940's flat bar bender, 3/4 UNF threads, all the adjusters were stretched.
2 weeks ago made another face plate for the Laguna wood lathe 1 1/4 UN8 thread form.
I don't have a bias towards any thread, it's just whatever I am repairing or making.
Rgds,
Crocy.