Isoplast Hardware
Isoplast fasteners are molded from an engineering thermoplastic polyurethane. E&T Fasteners offers Isoplast screws, hex head cap screws, nuts, and U-bolts, with the hex parts and U-bolts molded in a 40% glass-filled grade.
What Is Isoplast?
Isoplast is a rigid form of thermoplastic polyurethane (TPU), a polymer family that also includes soft, elastic grades. The manufacturer, Lubrizol, acquired the Isoplast line from Dow in 2009 and offers it in clear, impact-modified, and glass-filled grades.
Lubrizol describes the material as tough and dimensionally stable, like an amorphous resin, with the chemical resistance of a crystalline one. According to Lubrizol, it may be used in place of polycarbonate when stress cracking is an issue or when a polycarbonate part is difficult to color.
Properties of Glass-Filled Polyurethane Fasteners
The figures below are for 40% long glass-filled polyurethane, taken from our material properties charts.
| Property | Value |
|---|---|
| Tensile strength at yield | 27,000 psi (190 MPa) |
| Flexural strength | 40,000 psi (275 MPa) |
| Flexural modulus | 1,500,000 psi (10,000 MPa) |
| Elongation at failure | 2% |
| Notched Izod impact strength | 8 ft-lb/in (430 J/m) |
| Heat deflection temperature at 264 psi | 210°F (99°C) |
| Maximum service temperature | 150°F (65°C) |
| Water absorption, 24 hours | 0.11% |
| Dielectric strength | 500 V/mil |
| UL 94 flammability rating | HB |
| Specific gravity | 1.5 |
| Rockwell hardness | R119 |
Glass fiber nearly triples the tensile strength of the unfilled resins compared below. Elongation at failure drops to 2 percent, so the reinforced material is stiff rather than elastic.
At a specific gravity of 1.5, the material weighs a little more than half as much as aluminum. It is also an electrical insulator.
Isoplast 202 vs. 301
Isoplast 202 and 301 are two of Lubrizol's unfilled base resins, and 301 is a clear grade. The figures below come from Lubrizol's technical data sheets, using 202EZ, the current version of the 202 grade.
| Property | Isoplast 202EZ | Isoplast 301 |
|---|---|---|
| Tensile strength at yield | 10,000 psi | 10,000 psi |
| Elongation at break | 90% | 140% |
| Flexural modulus | 320,000 psi | 340,000 psi |
| Notched Izod impact, 73°F | 10 ft-lb/in | 2.4 ft-lb/in |
| Notched Izod impact, -40°F | 3 ft-lb/in | 0.8 ft-lb/in |
| Heat deflection temperature at 264 psi, unannealed | 240°F | 170°F |
The two grades are nearly equal in strength and stiffness. Grade 202EZ has about four times the room-temperature impact strength of 301 and a heat deflection temperature 70°F higher.
The glass-filled catalog parts on this page correspond to the properties table in the previous section rather than to these unfilled resins.
Isoplast Hardware From E&T Fasteners
Our Isoplast hardware line includes:
- Machine screws in five head styles: slotted round head, slotted fillister head, slotted flat head 82°, Phillips flat head 82°, and Phillips fillister head.
- Hex head cap screws, sometimes referred to as Isoplast hex bolts, are available in standard hex head and flanged hex head styles.
- Nuts, including hex nuts and Isoplast flange nuts.
- Extended reach U-bolts for securing large-diameter pipe and conduit, in sizes from 1 in to 6 in with 3/8-16 to 5/8-11 threads.
Frequently Asked Questions
How does Isoplast compare to glass-filled nylon?
Glass-filled Isoplast and 30% glass-filled nylon 66 are close in tensile strength. Isoplast absorbs about one-eighth as much water over 24 hours, so it is less prone to swelling in wet or humid conditions. The nylon tolerates more heat, with a maximum service temperature of 230 to 240°F.
What does "long glass-filled" mean?
Long glass fiber reinforcement gives a resin better impact resistance than short glass fiber, while keeping the strength and stiffness that glass adds. E&T's extended reach U-bolts, for example, are molded in a 40% long glass fiber resin.
What if I need a size that is not listed?
Along with catalog stock, we produce custom parts to a customer's print or sample. Send us your request through our quote form or contact page, and our team will review it.