Fillet Weld Sizes as per AWS D1.1 & AWS D1.2

This blog here answers your questions about:

  • What is the tolerance for Fillet weld sizes as per AWS D1.1 ?
  • What is the weld size tolerance?
  • What is the required fillet weld size for structures ?

Selection of Fillet Size

fillet weld size

Acceptance criteria clauses for Weld Profile in AWS

7.23.1 Fillet Welds. The faces of fillet welds may be slightly   convex, flat, or slightly concave as shown in Figure 7.4

and as allowed by Tables 7.8, 7.9, 8.1 , and 10.15.

Recommended weld profile in AWS

weld profiles-AQC

Recommended weld profile

fillet weld profiles

fillet weld

Allowable reduction in throat Convexity

weld profile

Conclusion for AWS D1.1

  • Minimum size (leg length) of fillet weld to be achieved as per Table 7.7 , the same shall be in the drawing too.
  • Under size of leg length is not acceptable, Throat thickness convexity acceptance criteria is from Table 7.9
  • Over size is not described in the standard, but can be mutually agreed between client and manufacturer through contract document, if not additional Fillet size is allowable
  • But the Weld profile or re-inforcement should be as allowed in the figures shown above.

In AWS D1.2 (Aluminium)

fillet welds

Tolerance as per AWS D1.2

acceptance criteria

Conclusion for AWS D1.2 (Aluminium)

  • Maximum convexity & Maximum Undersize is given in above table
  • Excess Weld Size is not a criteria for rejection as per AWS D1.2 as there it is not mentioned in the standard,
  • Again the if required the maximum size shall be mentioned in the drawing with mutual agreement between the client and manufacturer, or shall be specified in the contract document.


American Welding Society AWS D1.1 , AWS D1.2

we provide standard specifications for welding procedures for all welding process and Brazing. We offer Welder Procedure Specification, Welder Certificate Renewal Process, Procedure Qualification Record, Welder Qualification Testing, welder Training and Welder qualification services  in Coimbatore, Trichy, Salem, Erode, Chennai.

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