| Edge prep form | Thickness (mm) | Root face (mm) | Root gap (mm) | Reinforcement (mm) | |---|---|---|---|---| | C2 (single V) | 3–26 | 2 ±1 | 2 ±1 | 1–3 | | C4 (double V) | 12–60 | 3 ±1 | 3 ±1 | 1–3 | | C8 (square edges) | 1–4 | none | 0–1 | ≤1.5 |
| Joint type | Symbol | Description | |------------|--------|-------------| | Butt | C (Cтык) | Two plates in the same plane | | T-joint | T (Тавр) | One plate perpendicular to another | | Lap | H (Ha) | Overlapping plates | | Corner | Y (Уг) | Parts at an angle (usually 90°) | gost 5264-80 english pdf
Each type has multiple (e.g., C2, C4, T1, T3, H1, У2) depending on thickness and welding access. 4. Edge Preparation and Weld Dimensions (Examples) For butt joints (Type C): | Edge prep form | Thickness (mm) |