Welding Symbol Reference

Weld at the junction of two surfaces at approximately right angles. Most common weld type.

すみ肉溶接

Fillet welds on both sides. Approximately twice the strength of single fillet.

両側すみ肉溶接

Butt weld with V-shaped groove preparation. Used for thicker plates.

V形開先溶接

V-groove from both sides. Reduces welding distortion.

X形開先溶接

U-shaped groove. Less weld metal than V-groove, suitable for thick plates.

U形開先溶接

J-shaped groove. Used for groove welds on T-joints.

J形開先溶接

Single bevel groove. Half of V-groove shape on one side only.

レ形開先溶接

Double bevel groove from both sides. Used for T-joints.

K形開先溶接

Butt weld without groove preparation. Used for thin plates (6mm or less).

I形開先溶接（突合せ）

Circular hole in one overlapping plate filled with weld metal.

プラグ溶接

Elongated hole in one overlapping plate filled with weld metal.

スロット溶接

Resistance welding. Overlapping plates clamped by electrodes, welded at points.

スポット溶接

Continuous spot welding using rotating disc-shaped electrodes.

シーム溶接

Welding with backing material on reverse side. Prevents burn-through.

裏当て溶接

Depositing weld metal on surface. Improves wear/corrosion resistance.

肉盛溶接

Welding round bars together or to plate. Curved surfaces form the groove.

フレアV形溶接

Welding round bar to flat plate. Bar curve forms one side of groove.

フレアレ形溶接