Monthly Archives: August 2017

MeasuringtheMeltingPointOfWaxesUsedinInvestmentCasting

The melting point of wax is important to both the wax supplier and the investment casting foundry.

Wax manufacturers run tests as a part of quality control and wax development; foundries run tests on incoming waxes to determine melting time injection temperature and autoclave.

Various organizations have testing methods that are applicable to the investment casting industry such as ASTM1 {American Society for Testing Materials), and ICl2 (Investment Casting Institute). One problem that arises, however, is that melting point means different things to different people.

The melting point is usual1y defined as the temperature at which a substance makes a transition from the solid or semisolid state to the liquid state. In the investment casting industry, there are other terms that are sometimes used synonymously, including congealing point, dropping point, drop melting point, and softening point. Each of these terms, however, has a very specific definition.

The congealing point is defined by the ASTM D938 method as “the temperature at which molten petroleum wax, when allowed to cool under prescribed conditions, ceases to flow.”

The dropping point is defined by ASTMD566 as “the temperature at which the wax passes from a solid to a liquid state.”

The drop melting point is defined by AS”TM 0127 as “the temperature at which material becomes sufficiently fluid to drop from the thermometer.” and lastly, the softening point is defined by ASTM E_8 as “the temperature at which a disk of the sample held within a horizontal ring is forced downward a distance of 1 inch, under the weight of a steel ball as the sample IS heated at st> C (9t>F’) per minute:” The Investment Casting Institute’s Determination of a Softening Point has a similar definition with the exception that it specifies the heating rate of 4° F per minute.

Compounding the problem of determining melting point is the fact that a wax can have many “melting points,” depending on which test method is used.

For this reason, an experiment has been conducted to compare some of the different test methods currently available for determining melting points. Goals of the experiment were to determine which test gave the most reproducible results, which test methods were most applicable, and to compare the results of one test with those of another.

Saffroshine is a 25-year young company, manufacturing Pattern Waxes for Investment Casting Industry. Inert and Stable compositions compatible with various production and dewaxing processes. Better dimensional consistency and consistency of the Pattern Waxes. We are an Indian Manufacturing Company supplying to various Investment Casting Foundries in India and Overseas.