Turning Beryllium Copper--Safe enough?

[themuffinman]

Hi, I have to turn a 5 different parts that call out Beryllium Copper as Material. Ive done some research on the material but I have been getting mixed opinions on its hazards...

Some say that machining it in general is enough to harm your lungs.
Others say it has to be smaller than half a micron.

Im not going to be grinding, just turning and milling.

Ive been trying to find someone with experience in cutting it to ask them, but no such luck. So if anyone has done so, please reply.

Thanks.

[Geof]

A similar question came up here on CNCzone in 2005 but I do not know how to find the post I did at the time so here it is repeated.(Obviously it was closer to the end of the year. )

Beryllium Copper:

This brought back memories from my apprenticeship some forty odd 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.

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.

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 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.

[Gabe Newell]

I do not know if the following is accurate.

Feature Article - Copper Beryllium Vs. Beryllium-Free Copper - 08/02

"Carlos Cruz Wilson, a metals specialist for Houston, TX-based National Bronze and Metals, Inc. - a producer and distributor of a range of copper and copper alloys in various forms and shapes - also feels the public outcry over copper beryllium is mainly caused by ignorance. "The health issues, although legitimate, can be controlled with the proper handling of the beryllium alloys, or even the beryllium metal itself," he states. "Only when beryllium-containing materials are ground, sanded, polished, welded, EDM'd or changed - producing a dust, fume or mist - will there be any risk of exposure. Turning, milling and drilling presently create no risk when done wet with the proper coolant.

"Only when these airborne particles are less than 10 microns in diameter are they able to penetrate the air sacs of the lungs, thus causing a high risk situation," Wilson continues. "For beryllium to cause disease, the particles must penetrate the air sacs of the lungs with repeated exposure. The person exposed also needs to be allergic to beryllium to get the disease, and statistics show that only about three to four percent of the population is susceptible to the effects of beryllium."

[Geof]

The post above matches the conclusion I came to during the reading I did for my post. Briefly stated Beryllium is a definite hazard under certain conditions but under other conditions is not a hazard at all. It is not necessary to be paranoid about it but it is wise to take the necessary precautions when it is being processed in a manner that creates dust.

[themuffinman]

Thanks for the information people! Im not going to be grinding and coolant will be used so Im no longer worried.

Now... to tell the man with the checkbook how much its going to cost him! ha ha.

[ksanalytical]

I deal with pure Be on a regular basis. I don't machine it, but it certainly is something that gets a lot of attention from the safety guys. As stated, breathing the fine particulates seems to be the main danger... If you'll be working with alloys like that, I can't imagine that a full face respirator would make a huge dent in the budget. I got one on eBay with spare cartridges for $60.

Good luck!

Ken

[packrat]

We used beryllium copper for cores in certain plastic injection molds where I worked. Grinding and EDM was used, one day they came in and said it would not be used anymore. No reason given, then I got a computer and internet and found out why!
Same place would make us use MEK to clean molds. Too bad they went out of business. I would sue