I just got a gallon of Mobil DTE 25 (which I found out is described as
a hydraulic oil). Viscosity ISO 46. I wanted to use this on my 13"
south bend lathe. The oil came in a second hand container and on the
container a hand written warning states that this oil will corrode
brass.

I went to the mobil website and saw that they have a spec for copper
corrosion with a ASTM D 130 standard and they state that it has a "1B"
result. I went to the ASTM site and found out that the standard
requires you to immerse a copper strip in the test oil which is heated
to a certain temp for 3 hours and then the strip needs to be examined
for corrosion. However to find out what a test result of "1B" means,
but you have to purchase the active standard for $9.

Is "1B" a test result of no corrosion to copper? Will this oil be
harmful to copper and its alloys? Brass, bronze, monel? Just curious.

Aloha, Russell

Had a problem on a power station steam turbine once with corrosion of copper
or brass strainers by an oil additive. You end up with some water in the oil
in steam turbines and it was the combination of moisture and additive in
this case. I have a feeling that we changed TO DTE Light, rather than from
it, I will try and remember to look it up when I am in the office on Monday.

"russell shigeoka" wrote in message
oups.com...
I just got a gallon of Mobil DTE 25 (which I found out is described as
a hydraulic oil). Viscosity ISO 46. I wanted to use this on my 13"
south bend lathe. The oil came in a second hand container and on the
container a hand written warning states that this oil will corrode
brass.

I went to the mobil website and saw that they have a spec for copper
corrosion with a ASTM D 130 standard and they state that it has a "1B"
result. I went to the ASTM site and found out that the standard
requires you to immerse a copper strip in the test oil which is heated
to a certain temp for 3 hours and then the strip needs to be examined
for corrosion. However to find out what a test result of "1B" means,
but you have to purchase the active standard for $9.

Is "1B" a test result of no corrosion to copper? Will this oil be
harmful to copper and its alloys? Brass, bronze, monel? Just curious.

Aloha, Russell

IIRC, the Copper Corrosion Test scale is 1 to 10, 1 being the lowest
corrosion rating. I have seen somewhere that ratings 1 to 3 are considered
"non-corrosive". I believe rating 1B means no measurable copper in solution
after the test, but that a change in colour of the copper has been observed.
Hope this helps.

Regards,

Chas.

(To email me replace 'xxx' with tango papa golf)

IIRC, the Copper Corrosion Test scale is 1 to 10, 1 being the lowest
corrosion rating. I have seen somewhere that ratings 1 to 3 are
considered
"non-corrosive". I believe rating 1B means no measurable copper in
solution
after the test, but that a change in colour of the copper has been
observed.
Hope this helps.

Regards,

Chas.

(To email me replace 'xxx' with tango papa golf)

This prompted me to check my copy of the Institute of Petroleum Standards,
and ASTM D130-34 is one of the normalised standards, equivalent to IP 154/95
or EN ISO 2160.

The standard is entirely based on colour, after cooking at 100 C for 2-3
hours (can be hotter and/or longer for lube oil). 1 is "light tarnish", 1a
being light orange and 1b dark orange. 2 is moderate tarnish, 3 is dark
tarnish, 4 is corrosion, various degrees of black.

So I wouldn't normally be worried about using a 1b product.