CrV steels in Chinese products 2

[Coctyle]

Can anyone explain why so many Chinese products such as hand tools use CrV steels (variations of 6150)? There are less expensive alloys that are far superior when heat treated in the range of 45 HRC to 55 HRC. Is chromium less expensive in China?

Really, why does anyone use 6150 for anything?

 

[tbuelna]

Why do you have an issue with Chinese hand tools made from 6150 steel? For the time being, there is still a free market in most countries. So you are free to purchase whatever quality hand tool is available.

95% of the world's chromium currently comes from Africa and Kazakhstan.

 

[metman]

Quote: Really, why does anyone use 6150 for anything?

If I recall correctly, 6150 is used extensively for vehicle leaf springs and therefore I will guess that it provides good fatigue properties. In other words, maybe a high (endurance limit)/$ ratio?

As for using for hand tools, I have no clue - as you suggest, maybe availability of materials.

Design for RELIABILITY, manufacturability, and maintainability

 

[metman]

Ooops.

Maybe I should say, "...high[(endurance limit)*LBS]/$ ratio?"

Design for RELIABILITY, manufacturability, and maintainability

 

[Coctyle]

tbuelna - Did I say that I had a problem with Chinese hand tools? No, I did not. I was just asking a technical question about material choice. Don't be so quick to get offended.

 

[tbuelna]

Can anyone explain why so many Chinese products such as hand tools use CrV steels (variations of 6150)? There are less expensive alloys that are far superior when heat treated in the range of 45 HRC to 55 HRC. Is chromium less expensive in China? Really, why does anyone use 6150 for anything?

No problem, I took no personal offense from your post. It was just your use of "less expensive alloys", "far superior", and "Really, why does anyone use 6150 for anything?" that caused me to assume you had an issue with Chinese tools made from 6150.

Spend the extra money and buy hand tools from Snap-On or Matco. You'll be glad you did.

 

[1gibson]

Maybe a convenient raw material form is readily available. Scrap from automotive manufacturing?

 

[MintJulep]

Because at one time high-quality tools were made of CrV.
Because stamping "Chrome-Vanadium" on a crap tool gives it an appearance of a quality tool to the uninformed target market.

 

[Coctyle]

MintJulep...I think you hit the nail on the head.

tbuelna...Buying from Snap-on is excellent advice.

 

[CoryPad]

6150 and other CrV steels are popular for springs and fatigue strength. This is part of the reasoning for usage in other products, including tools. Here is a little blurb about using (or not using) 6150 for hose clamps. It is one data point to support "Why does anyone use 6150 for anything?". MintJulep's statement about part marking/marketing is true.

 

[Maui]

We use 6150 to manufacture machine clamping springs as well as a variety of collets for holding parts during machining. You will also find it used extensively as a backing steel in commercial bimetal bandsaw blades where a high speed steel cutting edge is laser welded or electron beam welded to a 6150 backer. Considering the cost and the combination of properties 6150 possesses in the heat treated condition, in the right application it is hard to beat this grade of steel.

Maui

 

[EdStainless]

Have you ever looked at Russian (actually USSR) equipment? The alloys are sometimes bizarre.
People work within their local constraints, and come up with different solutions.
If it works then it is fine.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[tbuelna]

EdStainless- Here's my personal experience with an alloy I saw used on a piece of Russian equipment. A few years back I had the opportunity to walk through an AN-124 accompanied by one of the flight crew that spoke English. In the cargo bay of the AN-124 there are a pair of overhead gantry cranes that can be used to load large payloads. I recall looking at the cargo hooks on the gantry cranes and noticed they were made from a beautifully machined and polished forging with a lustrous bare metal finish. I asked the Russian flight engineer what they were made of and he casually said "titanium". At first I found it hard to believe these parts were made from titanium forgings, but then the Russian flight engineer explained to me that titanium was very cheap and plentiful in his country.

 

[weldstan]

tbuelna,
And don't forget - lighter weight.