Materials,Parts and Finishes

An abrasive is defined as a material of extreme hardness that is used to shape other materials by a grinding or abrading action. Abrasive materials may be used as loose grains, as grinding wheels, or as coatings on cloth or paper. They may be formed into ceramic cutting tools that are used for machining metal […]

ABS plastics

ABS plastics are a family of opaque thermoplastic resins formed by copolymerizing acry-lonitrile, butadiene, and styrene (ABS) monomers. ABS plastics are primarily notable for especially high impact strengths coupled with high rigidity or modulus. Consisting of particles of a rubberlike toughener suspended in a continuous phase of styreneacrylonitrile (SAN) copolymer, ABS resins are hard, rigid, […]

Acetal plastics

Acetals are independent structural units or a part of certain biological and commercial polymers, and acetal resins are highly crystalline plastics based on formaldehyde polymerization technology. These engineering resins are strong, rigid, and have good moisture, heat, and solvent resistance. Acetals were specially developed to compete with zinc and aluminum castings. The natural acetal resin […]


Acetylene is a colorless, flammable gas with a garlic-like odor. Under compressed conditions, it is highly explosive; however, it can be safely compressed and stored in high-pressure cylinders if the cylinders are lined with absorbent material soaked with acetone. Users are cautioned not to discharge acetylene at pressures exceeding 15 psig (103 kPa), as noted […]

Acrylic plastics

The most widely used acrylic plastics are based on polymers of methyl methacrylate. This primary constituent may be modified by copolymerizing or blending with other acrylic monomers or modifiers to obtain a variety of properties. Although acrylic polymers based on monomers other than methyl methacrylate have been investigated, they are not as important as commercial […]


These are materials capable of fastening two other materials together by means of surface attachment. The words glue, mucilage, mastic, and cement are synonymous with adhesive. In a generic sense, the word adhesive implies any material capable of fastening by surface attachment, and thus will include inorganic materials such as portland cement and solders such […]


Several types of alkyds exist. Alkyd coatings are used for such diverse applications as air-drying water emulsion wall paints and baked enamels for automobiles and appliances. The properties of oil-modified alkyd coatings depend on the specific oil used as well as the percentage of oil in the composition. In general, they are comparatively low in […]


An alloy is a metal product containing two or more elements as a solid solution, as an inter-metallic compound, or as a mixture of metallic phases. Except for native copper and gold, the first metals of technological importance were alloys. Bronze, an alloy of copper and tin, is appreciably harder than copper. This quality made […]

Alloy structures

Metals in actual commercial use are almost exclusively alloys, and not pure metals, since it is possible for the designer to realize an extensive variety of physical properties in the product by varying the metallic composition of the alloy. As a case in point, commercially pure or cast iron is very brittle because of the […]

Allylics (Diallyl Phthalate Plastics)

Allylics are thermosetting materials developed since World War II. The most important of these are diallyl phthalate (DAP) and diallyl iso-phthalate (DAIP), which are currently available in the form of monomers and prepolymers (resins). Both DAP and DAIP are readily converted to thermoset molding compounds and resins for preimpregnated glass cloth and paper. Allyls are […]