Plastic Fastener Material Selection Guide, Performance Comparison Of PA66,PEEK,PPS Screws
plastic fasteners are widely adopted in semiconductor equipment, chemical plants, medical instruments and PV modules for insulation, non‑magnetic property, corrosion resistance and light‑weight advantages. Many buyers simply select general‑purpose nylon fasteners without checking material limits, resulting in mass failures such as high‑temperature softening, chemical erosion and fracture. Polymer grades differ significantly; operating temperature, chemical media and mechanical load shall be fully considered during selection.
PA66 nylon is the most cost‑effective general‑grade material. Glass‑fiber‑reinforced PA66 delivers higher mechanical strength. Continuous operating temperature ranges ‑40℃～120℃. Resistant to weak acid & alkali yet vulnerable to strong oxidants and concentrated acid. Water absorption causes slight dimensional swelling and strength drop. Suitable for indoor electrical cabinets and low‑voltage insulation assembly. Most stock plastic screws are made of PA66.
PPS (Polyphenylene sulfide) is mid‑range high‑temperature engineering plastic. Continuous service temperature reaches 200‑220℃ with negligible water absorption and stable dimension. It resists most acid, alkali and organic solvents, yet it is relatively brittle with limited impact resistance. Widely used for high‑temperature ovens, chemical components and PV inverter internal connections. Its cost sits between glass‑filled PA66 and PEEK.
PEEK (Polyetheretherketone) belongs to high‑performance special polymer. Long‑term working temperature reaches 240‑260℃. It combines high strength, creep resistance and outstanding chemical compatibility together with wear‑resistance, insulation and non‑magnetic features. It can partially replace metal fasteners for semiconductor vacuum chambers, analytical instruments and medical devices. Its major drawback is high raw‑material and processing cost, only justified for harsh working‑conditions.
PTFE (Teflon) provides supreme chemical resistance against almost all corrosive media, yet its mechanical strength is low and creep deformation easily occurs under pre‑load. It is mainly applied for gaskets and low‑load locating screws instead of high‑torque fastening joints. PC and PP are only recommended for light‑duty spacing rather than load‑bearing connection.
Practical selection rules: Glass‑filled PA66 for ordinary indoor insulation; PPS for combined high‑temperature & corrosion environment; PEEK for ultra‑heat, vacuum and cyclic‑load semiconductor equipment; PTFE for heavy‑chemical‑attack with minor load. Assembly torque must be much lower than metal bolts, over‑torque will crack plastic threads immediately.
Procurement tips: Request material certificates to distinguish virgin polymer from recycled compound. Minor grainy texture is normal for glass‑fiber reinforced grades. Perform thermal‑aging test for high‑temperature application to evaluate long‑term strength degradation.