Table J2.5 · Welded Joint StrengthAISC 360 J2.5: PJP vs Fillet Weld Strength
AISC 360-22 Table J2.5 gives PJP groove weld tension a weld-metal factor of phi = 0.80, while fillet weld shear uses phi = 0.75. The difference is limit-state framing: PJP tension accounts for unfused-root notch uncertainty, not fillet-style shear on a throat plane.
The Short Answer
Do not read the PJP groove weld row and the fillet weld row in AISC 360-22 Table J2.5 as competing answers to the same limit state. For a PJP groove weld loaded in tension normal to the weld axis, the weld-metal row gives nominal stress 0.60FEXX with phi = 0.80. For a fillet weld loaded in shear, the weld-metal row gives 0.60FEXX with phi = 0.75. They share a nominal stress expression, but they do not share the same mechanics.
The commentary explains the distinction. In §J2.4, the 0.60 factor for PJP tension exists to compensate for the unfused-root notch effect and uncertainty in root quality because PJP groove welds are typically not subjected to nondestructive evaluation. It does not mean the tensile failure mode is shear on the effective throat, which is the way fillet welds are framed.
AISC Commentary
§J2.4separates the PJP tension rationale from fillet throat shear: the PJP reduction accounts for root uncertainty and does not turn the PJP tension check into a fillet-style shear check.
Table J2.5 Comparison
The practical confusion usually starts because both rows show 0.60FEXX. The design factors and effective-area references tell you that the checks are not interchangeable.
| Weld condition | AISC 360-22 Table J2.5 weld-metal row | What that means |
|---|---|---|
| PJP groove weld, tension normal to weld axis | phi = 0.80, Omega = 1.88, nominal stress 0.60FEXX, effective area per J2.1a. |
A groove-weld tension check with the unfused-root notch effect already reflected in the nominal stress. |
| PJP groove weld, shear parallel to weld axis | phi = 0.75, Omega = 2.00, nominal stress 0.60FEXX, effective area per J2.1a. |
A shear check, not the same row as tension normal to the weld axis. |
| Fillet welds, including fillets in holes and slots and skewed T-joints | phi = 0.75, Omega = 2.00, nominal stress 0.60FEXX, effective area per J2.2a. |
A fillet-weld throat-shear check. |
Why PJP Tension Is Not Fillet Shear
For PJP groove welds in tension normal to the weld axis, Table J2.5 separates base metal and weld metal. The base-metal row points back to §J4, uses nominal stress Fu, and applies phi = 0.75. The weld-metal row uses 0.60FEXX and phi = 0.80. §J2.4 then tells you the available strength of welded joints is the lower value from the base material strength and the weld metal strength.
That is why the answer is not "PJP tension is always phi 0.80." It is "the weld-metal side of the PJP tension-normal-to-axis check uses phi 0.80, and the joint still has to pass the base-metal check and the geometry-dependent effective-area check." If the base material rupture limit state controls, the PJP weld-metal factor is not the controlling factor.
Why Fillet Welds Stay at Phi 0.75
Fillet weld strength is built around the effective throat area. AISC Commentary J2.4 describes the nominal strength as the lowest value from shear transfer through the weld effective throat, shear through the base metal along the fusion boundary, and base-metal rupture on the faying surface. That is why the fillet row in Table J2.5 uses the fillet effective area reference, J2.2a, and the shear design factor phi = 0.75.
So the difference between PJP tension and fillet shear is not an editorial inconsistency. A PJP groove weld has an unfused root, and the commentary says the 0.60 factor accounts for the notch and root-quality uncertainty. A fillet weld is designed through its effective throat as a shear plane. Different framing, different row, different factor.
PJP Plus Reinforcing Fillet
The common field detail is a PJP groove weld with a reinforcing fillet. This is where the shortcut can become unsafe or just wrong: do not add the PJP effective throat to the fillet throat and then pick whichever phi looks favorable.
§J2.5 says that if two or more general weld types are combined in a single joint, the strength of each is separately computed with reference to the axis of the group to determine the strength of the combination. Commentary §J2.5 then gives the special geometry warning for a combined PJP groove weld and fillet weld in the same joint: the total throat dimension is not the simple addition of the fillet weld throat and the groove weld throat. Determine the resultant throat, meaning the shortest dimension from the root to the face of the final weld, and design from that dimension.
If the governing load path is PJP groove weld tension normal to the weld axis: start with the PJP tension row and its weld-metal factor, then check base metal and the resultant throat geometry.
If the fillet is being treated as a separate fillet weld load path: use the fillet weld row and its throat-shear factor for that part of the joint.
If the result depends on 0.75 versus 0.80: the detail probably needs a clearer design statement, because the factor should follow the limit state and load path, not the presence of reinforcement alone.
Design Checks That Still Matter
AISC §J2.4 is explicit that welded joint available strength is the lower value of base material strength and weld metal strength. For PJP tension normal to the weld axis, that means the base-metal row in Table J2.5 is not optional. The joint may be governed by base-metal rupture, weld-metal strength, effective throat geometry, eccentricity, group action, or project-specific requirements.
For a combined PJP-plus-fillet detail, the clean workflow is to identify the load direction, identify whether the welds are acting as a combined groove/fillet joint or as separately designed weld elements, compute the correct throat or effective areas, and then apply the Table J2.5 row that matches each limit state. The table factor follows the check. It does not follow the label "reinforcing fillet" by itself.
Common Mistakes
Using 0.75 for the whole joint because a fillet is present. A reinforcing fillet does not automatically convert the whole joint into a fillet weld shear check.
Using 0.80 for everything because the detail began as a PJP groove weld. The fillet row still exists, and PJP shear parallel to the weld axis also uses phi = 0.75.
Adding throats arithmetically. Commentary J2.5 says the combined PJP-plus-fillet throat is not the simple addition of groove throat and fillet throat. Use the resultant throat from root to final weld face.
Ignoring the base metal row. Table J2.5 points PJP tension base metal to Section J4. The weld-metal phi value alone is not the joint capacity.
Review note: When the detail is a PJP groove weld with a reinforcing fillet and the result is sensitive to phi = 0.75 versus phi = 0.80, treat that as a design-clarity problem. State the intended load path and resultant throat before the factor argument.
Frequently Asked Questions
AISC 360-22 Table J2.5 gives the weld-metal check for a PJP groove weld in tension normal to the weld axis as 0.60FEXX with phi = 0.80. Commentary J2.4 explains why the 0.60 factor is there: it compensates for the unfused-root notch effect and uncertainty in root quality because PJP groove welds are typically not subjected to nondestructive evaluation. The commentary also says this does not mean the tensile failure mode is shear on the effective throat like a fillet weld. That is the key distinction. The table is not saying PJP tension is stronger because it has a fillet-like throat. It is using a groove-weld tension limit state with a root-uncertainty reduction already built into the nominal stress.
For fillet welds, AISC 360-22 Table J2.5 treats the weld-metal limit state as shear on the effective throat, with nominal stress 0.60FEXX and phi = 0.75. Commentary J2.4 frames fillet strength around the effective throat area and the available shear-transfer planes through the weld and adjacent base metal. That is a different mechanics picture from PJP groove weld tension normal to the weld axis. The two rows both use 0.60FEXX, but they are not the same design check. Fillet weld design is throat-shear based; PJP tension normal to the weld axis is a groove-weld tension check with an unfused-root notch allowance embedded in the nominal stress.
No. AISC 360 Commentary J2.5 says that for a combination PJP groove weld and fillet weld contained within the same joint, the total throat dimension is not the simple addition of the fillet weld throat and the groove weld throat. The resultant throat of the combined weld must be determined as the shortest dimension from the root to the face of the final weld, and the design is based on that dimension. This is why a reinforcing fillet cannot automatically be converted into extra strength by adding leg-size throat to the specified PJP effective throat. The geometry of the final combined weld controls the resultant throat.
Start by deciding what joint and load path you are actually designing. AISC 360 Section J2.5 says that when general weld types are combined in a single joint, the strength of each is separately computed with reference to the group axis to determine the strength of the combination. Commentary J2.5 adds the special geometry rule for a PJP groove weld plus fillet weld in the same joint: determine the resultant throat, not a simple throat sum. If the governing check is still PJP groove weld tension normal to the weld axis, Table J2.5 gives the weld-metal row as phi = 0.80. If you are designing a separate fillet weld shear load path, the fillet row uses phi = 0.75. Do not choose the factor only because reinforcement is present.
Yes. AISC 360 Section J2.4 says the available strength of welded joints is the lower value of the base material strength determined according to the tensile and shear rupture limit states and the weld metal strength determined according to Section J2.4. Table J2.5 reflects that split for PJP groove welds in tension normal to the weld axis: the base-metal row points to J4 with phi = 0.75 and nominal stress Fu, while the weld-metal row gives 0.60FEXX with phi = 0.80. The design answer is not found by reading only the weld-metal phi value. You still check base metal, weld metal, effective area, and any governing geometry or contract requirements.
Source: ANSI/AISC 360-22 Section J2.4, Table J2.5, Commentary J2.4, and Commentary J2.5, verified against the local source PDF and extracted corpus.