Mechanical Plastic Overview
The mechanical group of plastics are perhaps one of the largest groups of plastics in use in industry today.
The mechanical plastics discussed within these web pages are: ABS, acrylonitrile butadiene styrene; Acetal, Delrin II, Delrin AF, Hydex 302 & 4101, Noryl, Nylon 6/6, Nylon 6/12, Nylon MD, PET (polyethylene terephtalate), Polycarbonate, Polyurethane, Rexolite, UHMW (Ultra High Molecular Weight Polyethylene) and UHMW Static Dissipative.
Materials assigned to this product group are referred to as “mechanicals” because they demonstrate excellent performance when utilized in applications traditionally using materials such as metals for gears, bearing and other machine components subject to wear. These materials, like their metal counterparts, exhibit predictable performances that the mechanical engineer can specify in designing machined components.
This group of plastics also provide the user/designer with a unique combination of properties not inherent within metals such as: high resilience, high abrasion resistance, low frictional characteristics, lighter weight, and ease of fabrication. This group also possesses excellent impact resistance and good electrical properties.
Mechanical plastics aare available in a wide variety of forms: sheet, rod, tubing, film and special shapes.
For machined parts with high durability, and excellent machinability as well as outstanding electrical and mechanical properties, products fromt his group are strong candidates and should be the first to be considered.
| PROPERTY | ABS | ACETAL | DELRIN II | DELRIN AF | HYDEX 302 | HYDEX 4101 | NORYL | NYLON CAST | NYLON 6/6 | NYLON 6/12 | NYLON MD | PET | POLYCARBONATE | POLYSULFONE | POLYURETHANE | REXOLITE | UHMW |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PHYSICAL | |||||||||||||||||
| Specific Gravity | 1.05–1.07 | 1.41 | 1.42 | 1.54 | 1.05–1.10 | 1.15 | 1.14 | 1.06 | 1.14 | 1.39 | 1.20 | 1.24 | 1.03–1.5 | 1.05 | 0.94 | ||
| Water Absorption, 24 hr. (%) | 0.2–0.45 | .21–.22 | .25 | 0.20 | .05–.07 | 0.07 | 0.55 | .60–1.2 | 0.25 | .05–1.4 | 0.08 | 0.15 | 0.3 | 0.2–1.5 | 0.02–0.03 | <0.01 | |
| MECHANICAL | |||||||||||||||||
| TENSILE | |||||||||||||||||
| Strength, Yield (10³ psi) @ 73°F | 6.3–8.0 | 8.8–9.5 | 10.0 | 6.9–7.6 | 10–12 | 6.5–9.6 | 13.0 | 12–12.3 | 13.6 | 10.0–14.0 | 13.0 | 9.0 | 10.2 | .175–10 | 8.0–10.0 | 3.1–4.0 | |
| Elongation, Ultimate (%) @ 73°F | 5–20 | 21–40 | 50 | 15–22 | 200–300 | 8.3–13.5 | 4 | 4–6 | 150 | 5.0–150 | 4 | 135 | 360 | 100–1000 | 3 | 420–525 | |
| Modulus, Yield (10³ psi) @ 73°F | 330–400 | 410–420 | 420 | 420 | 280 | 340–360 | 480 | 410–455 | 290 | 450–600 | 490 | 300–350 | 360 | 10–100 | 240 | 80–100 | |
| FLEXURAL | |||||||||||||||||
| Strength (10³ psi) @ 73°F | 9.9–11.8 | 13 | 14.1 | 10.3–10.5 | 14 | 11.6 | 8.3–13.5 | 7.0–17.5 | 17.0 | 16.0–19.0 | 14.0–14.2 | 15.4 | .7–4.5 | 10.0–15.0 | |||
| Modulus, Yield (10³ psi) @ 73°F | 350–400 | 375 | 450 | 340–350 | 330 | 350–377 | 340–360 | 110–450 | 410–420 | 295 | 520 | 340–350 | 390 | 10–100 | 130–140 | ||
| Compressive Strength, 2% Offset (10³ psi) | 10.5–11.0 | 4.5 | 5.2 | 4.5 | 11.0 | 2.4 | 12.5 | ||||||||||
| Impact Strength — Izod, Notched (ft-lb/in) @ 73°F | 2.0–4.0 | 1.3 | 1.5 | .7–1.0 | 2 | 9–1.2 | 5.0–7.0 | 1.2 | .55–1.0 | 1.0 | 0.50 | 0.50 | 17 | 1.3 | 25 to flex | No break | |
| Hardness | R108–115 | M80 | M94–R120 | M78 | R120 | .35 / .19 | R113/119 | M88 | R120 | R114 | D80–90 | M95 | R118 | R120 | D90 | R110–120 | R64 |
| COEFFICIENT OF STATIC FRICTION | |||||||||||||||||
| Against self | 0.08 | 0.25 | 0.20 | 0.24 | 0.25 | 0.20 | 0.31 | ||||||||||
| Against steel | 0.15 | 0.06 | |||||||||||||||
| THERMAL | |||||||||||||||||
| Conductivity (BTU/Hr/Sq.Ft./°F/in.) | 0.96–2.16 | 1.6–1.92 | 2.6 | 1.5–1.7 | 1.5 | 1.35 | 1.8 | ||||||||||
| Coeff. of Thermal Expansion (10⁻⁵/°F) | 3.2–4.8 | 4.7–6.0 | 5.8 | 5.8–6.8 | 3.2 | 3.3–4.1 | 4.4 | 4.0–4.4 | 5.0 | 3.5 | 3.3 | 3.75–3.8 | 5.0 | 7.2 | |||
| Specific Heat (BTU/lb./°F) | 0.035 | 0.3–.4 | 0.4 | 0.30 | |||||||||||||
| HEAT DEFLECTION TEMP. (°F) | |||||||||||||||||
| At 66 psi | 215–225 | 315 | 334 | 290 | 302–328 | 200–279 | 370 | 410–455 | 356 | 400–490 | 240 | 275 | 158–174 | ||||
| At 264 psi | 185–223 | 230 | 210 | 244 | 240 | 185–265 | 180 | 194–200 | 194 | 200–470 | 175 | 270 | 345 | 200–225 | 118 | ||
| Max. Continuous Temp. (°F) | 210 | 210 | 195 | 122–221 | 220 | 220 | 220 | 180–200 | 210 | 215 | 160–180 | ||||||
| ELECTRICAL | |||||||||||||||||
| Volume Resistivity (Ohm/cm) | 2.7×10¹⁶ | 1×10¹⁴ | 10¹⁵ | 3×10¹⁶ | >10¹⁴ | >10¹⁵ | 10¹⁵ | 2.5×10¹³ | >10¹⁶ | >10¹⁶ | 5×10¹⁶ | 10¹⁵ | 10¹⁸ | ||||
| Dielectric Strength (V/Mil) | 385 | 500 | 500 | 400 | 400–630 | 1500 | 1500 | 300–400 | 1500 | 380–399 | 425 | 300–500 | 700–1200 | 450–500 | |||
| DIELECTRIC CONSTANT | |||||||||||||||||
| At 60 Hz | 2.8–3.2 | 3.7–3.9 | 2.65–2.8 | 4.0 | 4.0 | 4.0 | 3.3 | 3.0–3.17 | 3.07–3.03 | 4.0–7.5 | 2.55 | 2.3 | |||||
| At 1 MHz | 2.75–3.0 | 3.7–3.9 | 3.1 | 3.6 | 3.6 | 3.5 | 3.2 | 2.96 | 6.5–7.1 | 2.55 | |||||||
| DISSIPATION FACTOR | |||||||||||||||||
| At 60 Hz | 0.003–0.006 | .006–.0010 | .0004–.0007 | 0.025 | .01–.014 | 0.02 | 0.007 | 0.0009 | .0008–.0034 | 0.15–0.017 | <0.0005 | ||||||
| At 1 MHz | 0.008– | .005–.0010 | .005 | 0.009 | 0.0024 | 0.030 | .02–.04 | 0.02 | 0.020 | 0.010 | 0.1–0.6 | <0.0005 | |||||
| Arc Resistance (Seconds) | 240 | 220 | 183 | 120 | 120 | 122 | |||||||||||