Mitutoyo Threads

[pipeclay]

This is another worthless excercise,what does it matter.

[MuellerNick]

Well, did you notice the quotes around "course"?
Also, that article is doubtful. For example, it's missing the common M6 * 0.5. Or it says, that writing "M6 * 1" is OK. "M6" automatically means pitch 1 mm. Writing "M6 * 1" is only confusing and redundant. Also, there is no "superfine" pitch. It's either default or fine.

If you use the words "coarse" and "fine" in that context, it suggests that there is something in between. Like medium, standard or default.

You will finally fail, as soon as you use "M4 * 0.75 8.8". That thread doesn't exist and so there is no data for strength.

If Mitutoyo -for whatever reason- made up their mind to have a thread with a metric profile, an OD of 4 mm and a pitch of 0.75, it still isn't a "M4 * 0.75", It's not defined, there are no tolerances, no strength-data, nothing. If they call it "4 mm * 0.75", that's OK.

If you don't want to accept that a standard defines properties and everything that is outside of these defined properties doesn't follow the standard and can't be named like something that follows the standard. Well ... you also accept the Chinese label "CE" that looks very similar to the European CE-sticker. But the Chinese means "China Export" and is only intended as a fake for the unknowing.

Vice versa, I could say that "UNC 12 mm * 1.25" is right. It's the same nonsense.


Nick

[Steamwhisperer]

Well, did you notice the quotes around "course"?
Also, that article is doubtful. For example, it's missing the common M6 * 0.5. Or it says, that writing "M6 * 1" is OK. "M6" automatically means pitch 1 mm. Writing "M6 * 1" is only confusing and redundant. Also, there is no "superfine" pitch. It's either default or fine.

If you use the words "coarse" and "fine" in that context, it suggests that there is something in between. Like medium, standard or default.

You will finally fail, as soon as you use "M4 * 0.75 8.8". That thread doesn't exist and so there is no data for strength.

If Mitutoyo -for whatever reason- made up their mind to have a thread with a metric profile, an OD of 4 mm and a pitch of 0.75, it still isn't a "M4 * 0.75", It's not defined, there are no tolerances, no strength-data, nothing. If they call it "4 mm * 0.75", that's OK.

If you don't want to accept that a standard defines properties and everything that is outside of these defined properties doesn't follow the standard and can't be named like something that follows the standard. Well ... you also accept the Chinese label "CE" that looks very similar to the European CE-sticker. But the Chinese means "China Export" and is only intended as a fake for the unknowing.

Vice versa, I could say that "UNC 12 mm * 1.25" is right. It's the same nonsense.


Nick

Thanks Nick,
I learnt something new...again
I might have to re-visit Metric threads. I thought Metric was just Metric until now. Very informative, thanks.

Phil

[SiJ]

Hi Stu

Here's another thought - any chance it is a 8-36 UNF thread? That has close to 0.73mm pitch, very close to 4mm dia depending on fit class.

I have a (metric) Mitty Digimatic DTI which has No 4-48 threaded contact point (which was confusingly close to M2.5).

Cheers

Si

[MuellerNick]

This is another worthless excercise,what does it matter.

Call me evangelist, if it helps.

Might be it doesn't matter anything to you. That's OK.
But maybe you are not aware of of the advantages of standardisation? If everyone would make screws, nuts, bolts, washers, ball bearings, ... the way he thinks they should be, you would have a hard time making repairs.

Standards and interchangeable parts were a big leap forward for manufacturing. Just to name the stressed bolts and the fitting/tolerance system.

From a customer's POV:
Supposed you buy a granite plate that says "Grade AAA", but doesn't mention the standard. Useless!
Or you have a straight edge that says "DIN 875 / A". The grade are numbers, not letters. Useless again!

For sure, there are times when standard parts don't help.


Nick

[pipeclay]

The comment wasnt intended to reflect about standards but the disscusion in regards to the circles it was travelling in.

[nadroj]

There used to be a tool shop in Sydney, in the days before metrification in Australia when most fasteners were BS or US based. I used to go to "John's Metric Tool Store" for nuts and bolts for the Japanese motorbike I had then. The nice chap behind the counter politely advised me to not use expressions like "metric fine", ISO, JIS or DIN. He said all I really needed to know about the thread was the diameter and pitch - so just state those! I was convinced.

Jordan

[Anorak Bob]

There used to be a tool shop in Sydney, in the days before metrification in Australia when most fasteners were BS or US based. I used to go to "John's Metric Tool Store" for nuts and bolts for the Japanese motorbike I had then. The nice chap behind the counter politely advised me to not use expressions like "metric fine", ISO, JIS or DIN. He said all I really needed to know about the thread was the diameter and pitch - so just state those! I was convinced.

Jordan

Remember those useless Phillips head machine screws the Japs used, they made leaded 1214 look hard. And the chintzy tool kit packed under the seat. The good old days.

Ha Ha.

BT

[Ropetangler]

Remember those useless Phillips head machine screws the Japs used, they made leaded 1214 look hard. And the chintzy tool kit packed under the seat. The good old days.

Ha Ha.

BT

Yep BT, I remember, and I also remember replacing them all, or at least most of them, with "Unbrako" screws, no more stripped heads, no matter how many times I stripped it down, and no need to purchase new screws every time you took a screwdriver to it. Ahh, the memories of my beloved CB-72 Honda 250.
Rob.

[nadroj]

Remember those useless Phillips head machine screws the Japs used, they made leaded 1214 look hard.

They were awful alright, enough to make me notice that Euro bikes used high tensile
screws, even for modest duties.

Jordan

[nadroj]

Y Ahh, the memories of my beloved CB-72 Honda 250.
Rob.

That was a great bike! Even if the screws were cheesy.
Back in the late '80s I had a parts book for a CB72, with optional race parts listed. I showed it to a friend that had such a bike, who liked the seat and said he'd order one. I marvelled at his optimism - his bike was made in the mid-60s after all. Blow me down, but he rode over to my place with the Honda-supplied, racy humped back single seat a while later. It wasn't even too expensive. The Honda policy of making everything available for any Honda made was no myth - at least whilst Soichiro the founder was alive.

Jordan

[.RC.]

Not sure who devised the metric threading system, but it is pretty backwards compared to inch threading... It is about the only place I can think of where imperial is better then metric..

[MuellerNick]

but it is pretty backwards compared to inch threading...

What threading?

Bicycle threads?
CEI threads?
Whitworth threads?
UNC threads?
UNF threads?
UNEF threads?
UNR threads?
UNS threads?
8-UN threads?
12-UN threads?
16-UN threads?
BA threads
BSB threads?
BSW threads?
BSPP threads?

popcorn shares are rising!


Nick

[nadroj]

I think of imperial threads as brain exercise.
It's amazing anything got made!
The only real problem with them is the current scarcity of supply.

Jordan

[.RC.]

What threading?

Bicycle threads?
CEI threads?
Whitworth threads?
UNC threads?
UNF threads?
UNEF threads?
UNR threads?
UNS threads?
8-UN threads?
12-UN threads?
16-UN threads?
BA threads
BSB threads?
BSW threads?
BSPP threads?

popcorn shares are rising!


Nick

BA is reported to be a thread system based on the metre...

But what I was getting at was two things, firstly I come across enough odd pitched metric threads to know the metric thread system is just as bastardised with manufacturers using whatever pitch they feel like using.. There are plenty of constant pitch series in the metric standard.

Another point is the availability of metric bolts... Sizes like 9mm or 7mm while a metric standard are virtually non-existent as an off the shelf item in this country, but manufacturers are known to use them... Bolt head sizes are not standardized either....Bolt Depot - Metric Bolt Head, Wrench Size, and Diameter Table

Lastly imperial has the edge over metric on the cutting of threads on the manual lathe.... Imperial, one gear on the thread dial.... metric you need multiple gears and have to swap and change for different pitch threads...

The metric thread system is not the mark of simplicity that it may appear to be, it is just as bastardised as imperial is seen to be..