Engineering materials revision

Steel and plastics

Low-carbon steel

0.07-0.15%: Automobile body parts and wire products, rolling sheets, rivets, nails, chains

Mild carbon steel

0.15-0.3%: Structural steels used in building and fabrication

Medium carbon steel

0.3-0.6%: Automotive components and forgings, including shafts, axles, gears and crankshafts

high carbon steel

0.6-1.25%: High-strength spring materials and wires, cutting tools, files, drills, punches, dies and industrial knives

Ultra high carbon steel

1.25-2%: Highly tempered non-industrial-purpose knives, punches and axles

Polyethylene

Types: semi-rigid (LDPE), flexible (HDPE)

Properties: translucent, very tough, weatherproof, good chemical resistance, low water absorption, easily processed by most methods, low cost

Uses: squeeze bottles, carrier bags, chemical tank linings, chemical drums, toys, general packaging, gas and water pipes, cable insulation

Acrylonitrile butadiene styrene

Properties: good balance of properties, toughness/strength/temperature resistance coupled with ease of moulding and high quality scratch and wear resistant surface finish, rigid

Uses: automotive body parts, household electronics and electrical appliances and business equipment

Polypropylene

Properties: one of the most versatile polymers; semi-rigid, translucent, good resistance to chemicals, heat and fatigue, tough, integral hinge property

Uses: laboratory equipment, electronics and automobile products, buckets, bowls, crates, toys, medical components, bottle caps, fibres for carpets, sports clothing

Polylactic acid

Properties: low melting point, high strength, good layer adhesion, poor heat resistance, shiny and transparent, high grease and oil resistance

Uses: automobile interiors and medical implants, e.g. screws, plates, pins, rods, mesh

Polyvinyl chloride

Properties: corrosion and weather resistant, high strength-to-weight ratio, good electrical and thermal insulator

Uses: automobile parts, electronic and electrical equipment, water/waste drainage pipes and furniture

Nylon

Properties: tough, good thermal and chemical resistance

Uses: gears, rollers, guides, bearings and wear pads, textiles, fishing lines, film packaging