Flexural modulus
Stiffness in bending tests.
Flexural modulusGlossary
What Is Tensile Strength? Injection Molding Explained
Tensile strength is the peak stress a standard molded coupon reaches in tension before yield or break.
Glossary
Tensile strength is peak stress on a molded dumbbell coupon in tension
Datasheet tensile is a starting point before geometry and weld lines reduce effective strength.
Thin walls and knit lines lower real part strength compared with pristine test coupons.
Orientation from flow direction can make strength anisotropic on long filled parts.
FEA and DFM review adjust expectations beyond one datasheet row.
Engineering
Using tensile data without overclaiming
Connect coupon values to molded geometry.
- Boss roots and ribs need local section review, not bulk tensile only
- Weld lines across load path need explicit acceptance or redesign
- Glass filled grades gain stiffness but can lose ductility
Go deeper
Where this term connects
Each link is a different angle on the same program, not a duplicate definition.
Izod impact
Toughness versus strength.
Izod impactMelt flow index
Flow and fill related to orientation.
Melt flow indexPlastic molding
Qualified production programs.
Plastic moldingVisual reference
Photos from molding and tooling programs
Images are selected from the NetProto Forge media library for this topic.
Injection molded production parts on a tray
Injection molded production parts on a tray
Engineer reviewing a molded part drawing
Engineer reviewing a molded part drawing
Plastic housing components from a steel tool
Plastic housing components from a steel tool
FAQ
Tensile strength questions
Should I design to datasheet tensile only?
Use datasheets as starting points plus geometry review.
Does tensile predict snap fit retention?
Snap design needs strain and fatigue thinking beyond tensile peak.
Can weld lines be allowed in load path?
Only with explicit engineering acceptance on the drawing.
Next step
Upload load critical CAD
Mark features that need more than datasheet coupons.