beryllium copper

[trangt143]

I'm working on HAAS lathe, mostly on beryllium copper, i want to know how much feetrate for roughing and finishing, and also what is maximum rpm, lowest rpm, or mostly recommended rpm ? thank

[Technical Ted]

You'll have to give us a rough idea of what you are making.

Size of rough stock - OD & Length
Finish size - OD & Length
Are you drilling & or boring? If so what size ID?

What length are you chucking on?

[Geof]

Beryllium Copper:

This brought back memories from my apprenticeship some forty or so years ago when I got to machine stuff like this along with aluminum bronze, nickel alloys, etc, all with high speed tooling; YUCK! So because the grandchildren are at the other grandparents today I had a bit of free time (by the way; Merry Christmas) and went googling.

Everything between >> and << is what I found on different websites.

From one source:

>>Beryllium copper: Adding about 1.8% by weight of beryllium and about 0.2% cobalt to copper provides an alloy with strength comparable to many steels. The high strength, hardness, and thermal conductivity of the alloy promotes its use in high load bearings, especially where reliability is required under occasional overload, impact, high temperature, or marginal lubrication conditions. These alloys are used in electrically conducting applications and are frequently specified for aircraft landing gear and other airframe sliding surfaces.<<

So you could be working in the aerospace or electrical industry but so far no help with machining.

From another source:

>>High Copper Alloy. Beryllium Coppers are available in ductile, heat treatable tempers and in mill hardened tempers. Alloys are used in a wide range of applications requiring very high strength and stiffness with good conductivity. C17200 can develop more than 200 ksi (1380 MPa) tensile strength.

Applications Typical uses include electrical/electronic connectors, current-carrying springs, precision screw machined parts, welding electrodes, bearings, plastic molds and corrosion resistant components.

Machinability The machinability rating of this alloy is 20. (Where Alloy 360 FC Brass is 100). <<

I could not find what 100 meant but now we know you could also be in the mould business.

From another source:

>>Machinability
Beryllium copper alloys are readily machinable. In chip making operations, a reduction of 10-25% in machining time, can be seen when compared to tool steels.

Beryllium copper mold materials have hardness properties comparable to tool steels, but with superior thermal conductivity.<<

So obviously it is five times as difficult to machine as brass and up to one quarter easier than tool steel.

Rockwell hardness is 38 to 43.

And another source:

>>Machinability:

a) Beryllium copper can be machined into intricate shapes.

b) Its machinability in the age hardened condition is comparable to many other copper base alloys, and better than stainless steels.<<

Many copper based alloys are awful to machine and stainless steels range from fairly good such as the 303, 304 series through to **** awful for 700 series.

Then from another source which did not exactly have red lights flashing but fairly close!

>>b) Beryllium alloys are very hazardous to your health.

Health Information For Users Of Beryllium Alloys:
Please visit <http://www.ngkberylco.com/safety.html> for significant health safety information<<

This link has changed to:
http://www.ngkmetals.com/speaking.html


This sort of thing could attract your attention and cause a bit of concern so I went further but did not copy everything I read.

Pure Beryllium is definitely not a good thing to inhale or ingest in powdered form but the warning above under b) seems a bit extreme. Below is an abbreviated list of other comments from various sources.

>>Beryllium copper alloys contain very low levels of beryllium - generally between 0.5 and 1.85 percent. These materials pose no threat in solid form.
Beryllium copper in solid form does not emit beryllium "vapors."
Machining coolant does not become a hazardous waste after machining beryllium copper.
Beryllium copper has not been banned in Europe or any other country.<<

So to sum up:

Beryllium copper alloys are going to be similar or slightly easier to machine than tools steels or most stainless steels. My experience with HSS tooling was that speeds had to be down around 100 fpm with several degrees rake on the tool and we used kerosene as a cutting fluid (which was probably way more hazardous to my health than anything from the beryllium in the alloy).

Breathing dust from beryllium, or I would suggest alloys containg beryllium, is not a good idea. But then breathing copper dust is not a good idea so for dry grinding dust extractors on the machines and appropriate breathing protection on the operator is essential.

[DieGuy]

I machined a bunch of this about 25 years ago for use in a special electron beam coating machines where the electical properties were needed. We used carbide tooling on it mostly with good success, speeds and feeds like regualr O1 tool steel seemd to work A-OK. Back then we had no protective requirements but today I would assume that should not be the case. Altough the BE is tied up in a alloy I suspect that anything is possible.

We has a very special clean room type, negative pressure machine shop to machine the pure BE components. It has high vacumn systems for extraction of all chip, swarth. The place require ear protection, and respirators clothing change. That stuff will kill you if you are sensitive to it, the results are a nasty form of lung cancer.

[wisp]

DieGuy is right, beryllium copper is toxic. You should use caution when machining it. I would look up the MSDS on it and see what type of protection they reccomend.

[Billy Bird]

Forty or fifty years ago Honeywell Aero Div. had a BE machining facility. They had a very fancy air filtering system, special white work clothes, masks, a shift change shower room before leaving the area and ominous looking little gray boxes located through out the plant that continually (24 hrs.) took air samples remote from the machining facility. Maybe this was overkill maybe not but it was true.

[DieGuy]

http://www.southerncopper.com/pdfs/MSDS%20III.pdf

Looks like nasty stuff to me

[Geof]

Originally Posted by DieGuy http://www.southerncopper.com/pdfs/MSDS%20III.pdf Looks like nasty stuff to me

Did you read this link in detail? There seems to be a lot of scary information but a lot of it would apply to any metal alloy; for instance the bit about exposure to acids will generate hydrogen gas, all metals will.

There is absolutely no doubt that pure beryllium or alloys where beryllium is the major component need very special precautions but beryllium copper has less than 2% beryllium and does not present the same level of potential hazard.

We don't want trangt143 reading some of this stuff and having a heart attack. :frown: so here is a bit of calculation to try and put things in perspective.

One of the charts in that link gives a daily exposure limit of 0.002 mg per cubic meter. The most common way you get the stuff into the air is by grinding and this limit is reached by converting about 0.2 cubic inches of beryllium copper totally into dust, that remains suspended in the air and could be inhaled, inside a sealed room measuring 10feet by 10feet by 10feet.
And to reach the maximum permitted daily exposure a person would have to stay in this room for a full day.

If the person's job entailed polishing beryllium copper components day after day without dust extraction on the polishing machines and without any form of respiratory protection then they are on the borderline of what is within exposure regulations.

For someone running a lathe machining beryllium copper with flood coolant I think the biggest hazard present is that the piece of metal is going to come out through the window and smack them in the face.

[DieGuy]

Originally Posted by Geof Did you read this link in detail? There seems to be a lot of scary information but a lot of it would apply to any metal alloy; for instance the bit about exposure to acids will generate hydrogen gas, all metals will. <snip> For someone running a lathe machining beryllium copper with flood coolant I think the biggest hazard present is that the piece of metal is going to come out through the window and smack them in the face.

You are probably correct, most of the BE is bound in chip and very little would get free in a lathe operation. However one should be aware of the potenial hazard thay any BE exposure does have, studies have shown that it is the individual sensitivity to the metal and sometimes very small amounts have a large effect. I know that the chances of getting cancer are pretty slim form turing BE/CU but beryllium sensitization or chronic beryllium disease is possible.

The following quote comes from here These guys are one of the premier study centers for the diease characteristics of BE. I know because they have been bugging me for years to get tested. I figure that what is done is done, all I could do is get involved with a prolonged law suit with folks that have deep pockets.

Is beryllium hazardous? Handling beryllium in its solid form, such as a finished computer part that contains beryllium, is not known to cause illness. However, some people who inhale beryllium dust or fumes will develop beryllium sensitization or chronic beryllium disease (CBD). Although beryllium primarily affects the lungs, it can also cause a rash, poor wound healing, or wart-like skin bumps if it enters the body through an opening in the skin, such as through a sliver or cut. Although low levels of beryllium are found naturally in soil and air, there is not enough beryllium in the air or soil to cause beryllium sensitization or CBD from these sources alone. I’ve been exposed to an alloy that contains only a small amount of beryllium. Is this hazardous? Some commonly used alloys include beryllium copper (up to 4% beryllium), beryllium aluminum (20-60% beryllium), and beryllium nickel (0.275 to 7% beryllium){1}. Studies have shown that alloys that contain beryllium can be just as hazardous as pure beryllium metal. A 1999 report summarized two cases of CBD caused by copper alloy containing 2% beryllium {2}. Other studies have shown that breathing even seemingly trivial amounts of beryllium can cause beryllium sensitization and chronic beryllium disease {3,4}. Does beryllium cause cancer? Beryllium has been shown to cause cancer in humans and in many species of animals. Studies have confirmed the association between beryllium exposure and lung cancer in humans, especially in individuals with beryllium-related lung disease {5}. The International Agency for Research on Cancer (IARC) has classified beryllium as a human carcinogen. Importantly, the far more common health concerns for beryllium-exposed individuals are beryllium sensitization and chronic beryllium disease, as levels of exposure are generally lower now than they were many decades ago when some of the cancer studies were conducted. References: 1. Mroz MM, Balkissoon R, Newman LS. Beryllium. In: Bingham E, Cohrssen B, Powell C (eds.) Patty’s Toxicology, Fifth Edition. New York: John Wiley & Sons 2001, 177-220. 2. Balkissoon RC, Newman LS. Beryllium copper alloy (2%) causes chronic beryllium disease. J Occup Environ Med 1999; 41: 304-308. 3. Kreiss K, Mroz MM, Zhen B, Martyny JW, Newman LS. Epidemiology of beryllium sensitization and disease in nuclear workers. Am Rev Respir Dis 1993; 148:985-991. 4. Newman LS, Kreiss K. Non-occupational chronic beryllium disease masquerading as sarcoidosis: Identification by blood lymphocyte proliferative response to beryllium. Am Rev Respir Dis 1992; 145:1212-1214. 5. Steenland K, Ward E. Lung Cancer Incidence Among Patients With Beryllium Disease: A Cohort Mortality Study. J Natl Cancer Inst 1991; 83:1380-1385.

[trangt143]

sorry, just came back from Las Vegas yesterday, thank everyone, I got it....

On Milling Cnc machine, what is different between rigid tapping and tap attachment ???

[Geof]

Originally Posted by trangt143 ....On Milling Cnc machine, what is different between rigid tapping and tap attachment ???

Tapping with a tapping attachment is needed when the feed rate of the Z axis is not perfectly synchronized with the spindle rotation. The tapping attachment allows the tap to pull ahead or lag behind the motion of the Z axis.

Rigid tapping is when the spindle speed and the Z feed are exactly synchronized allowing the tap to be rigidly held in the spindle. The Z feeds at exactly the rate at which the tap must enter the hole.

[Konrad]

I know it is very very toxic!....I know a fellow, who got really sick from it, still suffering, this shop [fairly large] is not touching this stuff no more.
Konrad