Groove Weld Strength Calculator
Calculate CJP and PJP groove weld capacity per AWS D1.1 and AISC standards.
CJP vs PJP Comparison
| Attribute | CJP | PJP |
|---|---|---|
| Penetration | Full thickness | Partial depth |
| Joint Efficiency | 100% | Variable |
| Fatigue Category | Better (B-C) | Lower (D-E) |
| Backing Bar | Often used | Not required |
| Cost | Higher | Lower |
Groove Weld Design Principles
Complete Joint Penetration (CJP)
- Definition: Weld metal extends through the full thickness of the joint
- Strength: Effective throat = thickness of thinner plate joined
- Design: Tension/compression capacity equals base metal capacity
- Applications: Primary structural connections, pressure vessels, fatigue-critical joints
Partial Joint Penetration (PJP)
- Definition: Intentional incomplete penetration to reduce welding cost
- Effective Throat: Groove depth minus 3mm (1/8") for angles less than 60 degrees
- AWS D1.1: E = S - 3mm for groove angle 45-60 degrees; E = S for 60 degrees or more
- Limitations: Not permitted for certain fatigue applications and dynamic loading
AWS D1.1 PJP Effective Throat (E)
- Groove angle 60 degrees or more: E = depth of groove (S)
- Groove angle 45-60 degrees: E = S - 3mm (S - 1/8")
- J or U groove with 45 degrees or more: E = S