Plastic Thread Forming Screws
| Standard | OEM Standard / PT Screw Profile / Delta PT ref |
|---|---|
| Material | C1022 Case Hardened Steel |
| Strength Grade | Case Hardened |
| Size Range | ST3.5-ST6.3 / OEM range |
| Surface Treatment | Zinc Plated / Zinc Nickel / Zinc Flake |
01
Product Description
Product Description & Key Specifications
Plastic thread forming screws are designed to form internal threads in thermoplastic bosses, polymer housings and molded components without using a separate metal insert. This range uses C1022 case hardened steel and follows OEM standard, PT screw profile and Delta PT reference concepts for automotive and EV plastic assemblies.
These screws are not ordinary sheet metal screws. Thread geometry, flank angle, core diameter, point design and case hardening are selected to reduce boss cracking, improve pull-out resistance and support repeatable assembly torque in plastic. Final choice should be validated with the plastic material, boss design and installation torque window.
Zinc plated finish is used for general automotive interior and appliance assemblies, zinc nickel provides higher corrosion resistance for demanding OEM requirements, and zinc flake may be selected where coating performance and controlled thickness are required. Common RFQ sizes include ST3.5, ST4.2, ST4.8, ST5.5 and ST6.3 with OEM drawing lengths.
| Product type | Plastic thread forming screws / PT screws |
|---|---|
| Standards | OEM standard / PT screw profile / Delta PT reference |
| Material | C1022 case hardened steel |
| Strength grade | Case hardened |
| Size range | ST3.5-ST6.3 / OEM range |
| Common models | ST3.5 x 12, ST4.2 x 16, ST4.8 x 20, ST5.5 x 25, ST6.3 x 30 or OEM drawing |
| Thread type | Plastic thread forming profile by OEM / PT / Delta PT reference |
| Surface finish | Zinc plated / Zinc nickel / Zinc flake |
| Matched hardware | Plastic bosses, trim modules, polymer housings and EV component covers |
| Documentation | CoC, material certificate, coating report, dimensional report and PPAP-style support on request |
02
Selection
Selection Advantages by Application
Automotive Plastic Bosses
Thread forming screws are used in molded plastic bosses for interior trim, instrument panels, lighting modules and body electronics. Boss geometry and torque window should be validated before production.
Automotive and EV fastenersEV Battery and Electronics Housings
Zinc nickel or zinc flake coated thread forming screws can be specified for polymer covers, control housings and EV modules where coating performance and assembly repeatability matter.
EV fastenersAppliance and Industrial Plastic Components
C1022 case hardened screws are suitable for plastic covers, instrument housings and light-duty industrial polymer assemblies when the thread profile is matched to the plastic.
Industrial equipment fasteners03
Assembly
Recommended Matching Products
04
Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Cold heading and special thread rolling for plastic thread forming profilesC1022 material and wire diameter verification
Case hardening for thread forming performanceCase depth, core hardness and surface hardness checks when specified
OEM, PT screw profile or Delta PT reference geometryThread profile, point form, head dimensions and drive fit inspection
Zinc plated, zinc nickel or zinc flake coatingCoating thickness, corrosion test support and appearance review on request
Line-side packaging and OEM project supplyDimensional report, CoC and PPAP-style documentation support when required
05
FAQ
Common Questions Before RFQ
Can ordinary self tapping screws be used in plastic bosses?
They may crack bosses or give unstable torque. Plastic thread forming screws use profiles designed for molded plastic and should be validated with the boss design.
What is a PT or Delta PT screw?
These are thread forming screw profile concepts for plastic assemblies. The final geometry should follow the OEM drawing or approved reference.
Why is case hardening required?
Case hardening gives the screw surface enough hardness to form threads in plastic while maintaining core toughness for assembly loads.
Which coating should I choose?
Zinc plated is common for general use, zinc nickel offers higher corrosion resistance, and zinc flake may be selected for controlled coating performance.
Can PPAP-style documentation be supplied?
Yes. Dimensional reports, material certificates, coating reports and PPAP-style documentation can be supported when specified with the RFQ.
Need thread forming screws for plastic bosses?
Send your OEM drawing, plastic material, boss design, screw size, head and drive style, coating, torque requirement and documentation scope. We can quote C1022 case hardened screws for automotive and EV plastic assemblies.
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