Get help from Pros. Remove ads. Promote your CV or LinkedIn profile.

A hardness test performed by pressing a steel ball of standard hardness into a surface by a standard pressure.
a hardened steel ball of known diameter is applied to the specimen under a known loading for a period of 1 second.

The diameter of the impression resulting in the specimen is measured with a microscope. Hardness is indicated by the Brinell Number, derived by dividing the applied load in kilograms by the spherical area of the impression in square millimeters. The harder the material, the smaller the impression and consequently the higher the Brinell number. To keep the relationship between load P, diameter D and the impression produced within limits, for different materials, different P/D2 ratios are used. The following are approximate Brinell numbers, for the stated material.

Material Brinell Hardness Number
Bronze (Chill Cast) 32
Brass 60
Gunmetal 70 - 75
Mild Steel 110 - 130
Carbon Steel 150 - 200
Cast Iron 400

Related Terms

BUBBLE POINT

The differential gas pressure at which the first steady stream of gas bubbles is emitted from a wetted filter element under specified test conditions.

A.S.T.M.

American Society for Testing Materials - a society for developing standards for materials and test methods.

FABRICATION INTEGRITY POINT

The differential gas pressure at which the first stream of gas bubbles are emitted from a wetted filter element under standard test conditions.

FILTER LIFE TEST

A type of filter capacity test in which a clogging contaminant is added to the influent of a filter, under specified test conditions, to produce a given rise in pressure drop across the filter or until a specified reduction of flow is reached. Filter life may be expressed as test time required to reach terminal conditions at a specified contaminant addition rate.

BETA RATING

the method of comparing filter performance based on efficiency. This is done using the Multi-Pass Test which counts the number of particles of a given size before and after fluid passes through a filter.

BETA-RATIO (ß-RATIO)

The ratio of the number of particles greater than a given size in the influent fluid to the number of particles greater than the same size in the effluent fluid, under specified test conditions (see 'Multi-Pass Test').

FTIR, Fourier Transform Infrared Spectroscopy

A test where infrared light absorption is used for assessing levels of soot, sulfates, oxidation, nitro-oxidation, glycol, fuel, and water contaminants.

PAPER CHROMATOGRAPHY

A method which involves placing a drop of fluid on a permeable piece of paper and noting the development and nature of the halos, or rings, surrounding the drop through time. The roots of this test can be traced to the 1940s, when railroads used the 'blotter spot' tests.

POUR POINT

Lowest temperature at which an oil or distillate fuel is observed to flow, when cooled under conditions prescribed by test method ASTM D 97. The pour point is 3°C (5°F) above the temperature at which the oil in a test vessel shows no movement when the container is held horizontally for five seconds.

PATCH TEST

A method by which a specified volume of fluid is filtered through a membrane filter of known pore structure. All particulate matter in excess of an 'average size', determined by the membrane characteristics, is retained on its surface. Thus, the membrane is discolored by an amount proportional to the particulate level of the fluid sample. Visually comparing the test filter with standard patches of known contamination levels determines acceptability for a given fluid.
Get help from Pros. Remove ads. Promote your CV or LinkedIn profile.

Related questions

MarineProHelp 2018 - 2022