Metric Trapezoidal Threads (Tr) Chart
| BASIC DIMENSIONS AND PITCH | |||
|---|---|---|---|
| Tr designation | Basic major diameter (mm) | Pitch (mm) | Included angle |
| Tr 8 × 1.5 | 8 | 1.5 | 30° |
| Tr 10 × 2 | 10 | 2 | 30° |
| Tr 12 × 3 | 12 | 3 | 30° |
| Tr 14 × 3 | 14 | 3 | 30° |
| Tr 16 × 4 | 16 | 4 | 30° |
| Tr 18 × 4 | 18 | 4 | 30° |
| Tr 20 × 4 | 20 | 4 | 30° |
| Tr 24 × 5 | 24 | 5 | 30° |
| Tr 30 × 6 | 30 | 6 | 30° |
| Tr 36 × 6 | 36 | 6 | 30° |
| Tr 40 × 7 | 40 | 7 | 30° |
| Tr 50 × 8 | 50 | 8 | 30° |
| Tr 60 × 9 | 60 | 9 | 30° |
| Tr 80 × 10 | 80 | 10 | 30° |
| Tr 100 × 12 | 100 | 12 | 30° |
Common ISO metric trapezoidal combinations are shown. ISO 2902 defines the full general plan; ISO 2904 gives basic dimensions and ISO 2903-2:2025 gives size limits.