[Luis Van Damme]

Hardness is one I guess? Cheap Chinese Aluminium is little softer?

Same question for steels too.

[fizzissist]

Hardness is one I guess? Cheap Chinese Aluminium is little softer?

Same question for steels too.

Other than quality control, actually MEETING the alloying specs, MEETING the heat treat specs, MEETING the size tolerances.....
...Not sure what you mean?

[Luis Van Damme]

Other than quality control, actually MEETING the alloying specs, MEETING the heat treat specs, MEETING the size tolerances.....
...Not sure what you mean?

I mean that chinese aluminium is 15$ cheaper per kg than aluminium imported to china. I asked from one chinese cnc manufacturer about their aluminium quality and he didn't know the difference between the materials other than imported costs 15$ more per kg.

[ihavenofish]

I mean that chinese aluminium is 15$ cheaper per kg than aluminium imported to china. I asked from one chinese cnc manufacturer about their aluminium quality and he didn't know the difference between the materials other than imported costs 15$ more per kg.

2 obvious reasons:

- if they make it local, it costs less. less labour costs, less electrical power costs, less shipping costs. the same reasons alot of things in china are less money.

- they get heavy subsidies.

as for quality, its hard to say, if they are meeting the spec for the alloy as mentioned above, it should be fine. if you had the ability to test it somehow, you could get them to send you samples. were used to chinese companies skimping on quality due to low skill labour or cheap materials, but its hard to really skimp on something like an aluminium bar.

and... $15/kg more? its only $4/kg for 6061 here in canada.....

[CaptainVee]

Aluminium needs a huge amount of electricity. Thus Chinese aluminium will be more poluting and probably putting more co2 n to the air (if made from cal)

[fizzissist]

1. Chinese labor is, for the moment and foreseeable future, significantly cheaper. 2. Chinese power, being unregulated and not subject to the same strict environmental regulations that the west is, is cheaper.
3. Mining the raw materials in China is cheaper.
4. There are NO labor laws in China. (think Lao Gai)

1+2+3+4=A lot cheaper.

But the question wasn't cost, it was quality, was it not?

When I think Chinese quality, I think lack of. Like gluten, drywall, machine tools, everything Walmart. It's crap. It's Made In Japan 1960. But the big difference between those two is that China lies about everything.

They'll say it's +/-.005, but when you measure it, don't be surprised if it's not....if you get my meaning.

[DMF_TomB]

international metal cross reference from the book Jianming Wujin Shouce is attached
.
picture of page 1061 showing ASTM 6061 aluminum alloy and cross reference numbers for Chinese, UK, Russian, Japanese, USA, France, German, and a few i am not sure about.
.
since most Chinese Engineers can read and write many languages i would think most Americans can easily read this and understand all the world wide metal alloys numbers and their differences.
.
also i would think all American machinist should be able to open their copy of the Jianming Wujin Shouce or equivalent and look up world wide metal alloy standards themselves in 5 minutes or less. most Chinese Engineers i know can do this, it was part of their 1st year Engineering education.

[fizzissist]

Your point is well taken, and noted that you've been harping on this for over a year, anyway.

Maybe the engineers you've talked to were well educated, and I wouldn't question that. From MY personal experience, dealing with their scientists in U.S. schools the breadth of knowledge is, to say the least, from one extreme to the other.

My point was, and remains, is that despite knowing what the specs are, the delivered product can vary dramatically from the advertised.

On the issue of American machinists keeping up with their competition, I'll have to concede. We're losing ground, and THAT'S not their fault.

[jeffrey001]

It's easy to answer, they will say you that their alloy, aluminum or steel or stainless meets the metallurgy standard but this is not true.

We have a company near my shop where they make stainless steel drum made from 304, laser welded with Fanuc robots, they bought some drums from China which they said was made with 304 but when you put a magnet on it, is stick on it and you could see rust on some joints.

The alloy did not meet the standard for 304 stainless and you could see the difference in color and quality.

Just look at casting quality, nothing to compare with others.


Jeff

[DMF_TomB]

1) in China the best way to get the metal alloy you want is to ask for a Government Stamped Receipt with metal spec. Takes about 5 minutes to get spec faxed over and store to stamp a receipt. You will pay sales tax and more for the certified stamped receipt. If they do not give you what you have a stamped government stamped receipt for they can go to a Chinese jail for a long time. It is been my experience they will not mess with the government.

2) Chinese 304 Stainless is often what we call 321. And welding rod needs to be for 321 or welds will not be correct. Often their is confusion in a customer buying Chinese 304 (ASTM 321) thinking it is ASTM 304. Improperly used ASTM 321 if welded with ASTM 304 can sometimes cause problems.
........ Translation errors can cause big problems sometimes. Once a Chinese Engineer explained it to me I adjusted my buying practices by learning more about what I was actually buying. The problem was originally my ignorance of Chinese metal standards more than anything else.

3) In China go to any 4 star or higher hotel and at the bar you will see many experts from all over the world. Standing shoulder to shoulder with German, Swiss, American, etc experts I have seen many a American get their pride bubble burst after they realize their competitions experience and education level. Sometimes it takes months or years but eventually the Americans realize they are not the most important manufacturing country in the world. They haven't been for many decades now.

[RICHARD ZASTROW]

About those stamps, I saw a kid in a market stamping "silver" jewelry with a "government" proof mark.

Dick Z

[ihavenofish]

About those stamps, I saw a kid in a market stamping "silver" jewelry with a "government" proof mark.

Dick Z

no less than 2 major canadian bicycle builders and several us builders in the last decade or so have been caught putting "high end" 4130 tubing stickers on their bikes while using cheap junk.

people will lie to make a buck, its not limited to political boundaries.

as mentioned above, in china, much like in the US, if you lie about aerospace materials, the concequences are much more dire than on cheap consumer trinkets.

there is only one way to get what you want from any company in any country, communicate, inspect, and be prepared to pay fair value. if you are trying to force a companies employees into poverty to sell your junk to wallmart at rock bottom prices, then id be not surprised in the least if they provide a sub expectation part, or even mess with you out of spite.

[fizzissist]

So the cans were supposed to be 304, and we're told that in China 304 is 321, and we're told that you have to weld 321 with 321, but sometimes 321 is 304 or 304 is 321 and nobody checked that the welding rod was the correct rod for the job, and Americans are stoopid because we don't know, but the Chinese are superior because they have fat books....

Bottom line, my friends, is that the Chinese screwed up by not using the correct materials in manufacture, because they're 1. Incompetent, 2. They lied. 3. Both of the above.

"2) Chinese 304 Stainless is often what we call 321." What do you mean "often"??? Sometimes, but not all the time, maybe....well, we think so...not sure when....

I don't mind a lesson in humility..but you'd better be thoroughly correct if you're going to feed it to me.

And for the record....Chinese (of which there are 4 dialects!!!) may be the most predominate language by virtue of sheer population, but English is spoken in EVERY major international air control tower in the WORLD.

With the exception of Scotland and Louisiana shrimpers, I can speak and understand english anywhere in the world. My Chinese friend can't understand or speak fluently with people in her own country.

[dertsap]

Bottom line, my friends, is that the Chinese screwed up by not using the correct materials in manufacture, because they're 1. Incompetent, 2. They lied. 3. Both of the above.

.

everyone knows that china produces the best products in the world .
I've run numerous " Free machining " steel castings from china , and aside from the slag , air pockets and spots harder than carbide , I found them to be fabulous to machine

[jeffrey001]

When I went to New York, in Chinatown, you can buy a Rolex for $100.00 and it has the Rolex logo or stamp.

You could buy a $2000.00 bottle of perfume for $50.00 and it has the logo or stamp of the high end brand.

Could it be the same thing for metal alloy or every thing else, I think so.

Metal alloy is one of the most important standard for the industries, in order to build something that will meet the needs for security and productivity.

In China, if it's yellow, it's titanium coated

304 should be 304 and nothing else.

The drum I was talking about were for the food industries so no place for the

'' it is suppose to be or the I thik it is ''


Jeff

[fizzissist]

I'm hoping to get to China one day, and pick up my copy of Jianming Wujin Shouce Counterfeiting.

Haven't been able to find a copy of Jianming Wujin Shouce Hacking. Maybe it's still in gov't only circulation.

[Delw]

Chinese alum is anything they stamp alum.
sending a 1/2 endmill at 150 IPM and having it explode on you due to metal in the alum.
Or sending it to anodize and getting different results in color and surface finish.

[fizzissist]

Chinese alum is anything they stamp alum.
sending a 1/2 endmill at 150 IPM and having it explode on you due to metal in the alum.
Or sending it to anodize and getting different results in color and surface finish.

Delw,
Sometimes 2011 is 1018. Sometimes our 6061 is their 4140. Didn't you read the earlier posts? 304, 321, a yuan here, yuan there.... You're making it sound like a big deal.

When you go to a 4-star hotel in China and stand shoulder-to-shoulder with highly educated people from around the world...you'll find that they're in it for the profit. We're the source. (..if they know so much, why is the product so bad?)

[fizzissist]

Jay Leno Article

Would YOU fly on an airplane that used Chinese bolts??

[fizzissist]

Chinese alum is anything they stamp alum.
sending a 1/2 endmill at 150 IPM and having it explode on you due to metal in the alum.
Or sending it to anodize and getting different results in color and surface finish.

"...I know have an order to re-make his whole tooling range because the quality and consistency of the china produced parts are now increasingly getting worse.

I say give him a copy of the drawings and while you are there let them know it's been a pleasure doing business.

I now have a total of over 25 sets of tooling to remake because the land of the great wall has no quality control or any interest in my customers concerns about the quality of their product.

The amount of work I have picked up from ex-china "trading partners", is awesome. They appreciate my work more now that they are back. I didn't even have to hire titty girls and fancy hookers like the Chinese do to get their business..."
--Post #27

http://www.cnczone.com/forums/mechan...ml#post1039155