Trapezoidal thread
With trapezoidal threads , the profile of the threads has the shape of an isosceles trapezoid . The threads are thicker than those with a triangular profile that are generally used (for example with metric and Whitworth threads ) and also lead to larger pitch dimensions.
Trapezoidal threads are used to transfer movements and forces, for example on lead screws in lathes or in screw presses . The greater gradient is an advantage here. The thicker threads are suitable for transmitting larger axial forces before they fail due to shearing . In typical applications, self-locking, which is more moderate due to the greater slope, is tolerable or of no importance. Compared to the ball screw drive , the trapezoidal screw drive is significantly less efficient due to the sliding friction between the nut and the spindle.
The thread designation consists of the abbreviation “Tr”, the nominal diameter and the pitch; Tr 24 × 5 denotes a trapezoidal thread with a nominal diameter of 24 mm and a pitch of 5 mm (for comparison: a metric standard thread of the same diameter only has a pitch of 3 mm).
standardization
- Metric ISO trapezoidal thread DIN 103: Angle between matching flanks 30 ° ( standard thread 60 ° acute)
- Flat metric trapezoidal thread DIN 380: Angle between flanks that belong together 30 °, used for example in screw clamps
- Rounded trapezoidal thread DIN 30295
Metric ISO trapezoidal thread (DIN 103-1, -2, -4)
|
DIN 103 |
|---|---|
| Area | thread |
| title | Metric ISO trapezoidal thread |
| Brief description: | Part 1: Thread profiles, Part 2: Thread series, Part 3: Dimensions and tolerances for trapezoidal threads of general use, Part 4: Nominal dimensions, Part 5: Limit dimensions for nut threads from 8 to 100 mm nominal diameter, Part 6: Limit dimensions for nut threads from 105 to 300 mm Nominal diameter, Part 7: Limiting dimensions for bolt threads from 8 to 100 mm nominal diameter, Part 8: Limiting dimensions for bolt threads from 105 to 300 mm nominal diameter, Part 9: Gauges for bolt and nut threads; Gauge dimensions and construction features |
| Latest edition | 4.1977 (part 1 ... 4), 10.1972 (part 5 ... 8). 2.1985 (part 9) |
| ISO |
|
Nominal ø × pitch [mm] |
Flank ø [mm] |
Core-ø | Outer-ø [mm] |
|
|---|---|---|---|---|
| External thread ( screw ) [mm] |
Internal thread ( nut ) [mm] |
|||
| Tr8 x 1.5 | 7.3 | 6.2 | 6.5 | 8.3 |
| Tr10 × 2 | 9.0 | 7.5 | 8.0 | 10.5 |
| Tr12 × 3 | 10.5 | 8.5 | 9.0 | 12.5 |
| Tr14 × 3 | 12.5 | 10.5 | 11.0 | 14.5 |
| Tr16 × 4 | 14.0 | 11.5 | 12.0 | 16.5 |
| Tr18 × 4 | 16.0 | 13.5 | 14.0 | 18.5 |
| Tr20 × 4 | 18.0 | 15.5 | 16.0 | 20.5 |
| Tr22 × 5 | 19.5 | 16.5 | 17.0 | 22.5 |
| Tr24 × 5 | 21.5 | 18.5 | 19.0 | 24.5 |
| Tr26 × 5 | 23.5 | 20.5 | 21.0 | 26.5 |
| Tr28 × 5 | 25.5 | 22.5 | 23.0 | 28.5 |
| Tr30 × 6 | 27.0 | 23.0 | 24.0 | 31.0 |
| Tr32 × 6 | 29.0 | 25.0 | 26.0 | 33.0 |
| Tr34 × 6 | 31.0 | 27.0 | 28.0 | 35.0 |
| Tr36 × 6 | 33.0 | 29.0 | 30.0 | 37.0 |
| Tr38 × 7 | 34.5 | 30.0 | 31.0 | 39.0 |
| Tr40 × 7 | 36.5 | 32.0 | 33.0 | 41.0 |
| Tr42 × 7 | 38.5 | 34.0 | 35.0 | 43.0 |
| Tr44 × 7 | 40.5 | 36.0 | 37.0 | 45.0 |
| Tr46 × 8 | 42.5 | 37.0 | 38.0 | 47.0 |
| Tr48 × 8 | 44.0 | 39.0 | 40.0 | 49.0 |
| Tr50 × 8 | 46.0 | 41.0 | 42.0 | 51.0 |
| Tr52 × 8 | 48.0 | 43.0 | 44.0 | 53.0 |
| Tr60 × 9 | 55.5 | 50.0 | 51.0 | 61.0 |
| Tr70 × 10 | 65.0 | 59.5 | 60.0 | 71.0 |
| Tr80 × 10 | 75.0 | 69.0 | 70.0 | 81.0 |
| Tr90 × 12 | 84.0 | 77.0 | 78.0 | 91.0 |
| Tr100 × 12 | 94.0 | 87.0 | 88.0 | 101.0 |
| Tr120 × 14 | 113.0 | 104.0 | 106.0 | 122.0 |
- for the sizes see thread parameters
Web links
- Principle, storage, calculation of trapezoidal thread spindles . precifast.de. Retrieved April 21, 2014