UNI 8112 Standard Dimensions for Thread rolling screws, pan head and cross recessed
Thread rolling screws, pan head and cross recessed
The standard specifies the characteristics of hexagon head thread forming screws for connections. This type of threaded connection, if the screw is not replaced, offers a good tear resistance, since the clearance between the screw and nut is equal to zero. In addition, the friction between mating parts further increases the unscrewing torque. For the preparation of the holes diameters see UNI 8108.
Dimensional Drawing and Technical Diagrams
Key Dimensions and Technical Parameters
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Dimensions in mm - source UNI 8112 Publication date: 1993 |
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| d thread size | M 2 | M 2.2 | M 2.5 | M 3 | M 3.5 | M 4 | M 5 | M 6 | M 8 | |
| P | 0.4 | 0.45 | 0.45 | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 | |
| D max | 4 | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 16 | |
| D min | 3.82 | 3.82 | 4.82 | 5.82 | 6.78 | 7.78 | 9.78 | 11.73 | 15.73 | |
| k max | 1.72 | 1.72 | 2.12 | 2.52 | 2.82 | 3.25 | 3.95 | 4.75 | 6.15 | |
| k min | 1.48 | 1.48 | 1.88 | 2.28 | 2.58 | 2.95 | 3.65 | 4.45 | 5.85 | |
| r1 min | 0.2 | 0.2 | 0.26 | 0.3 | 0.35 | 0.4 | 0.5 | 0.6 | 0.8 | |
| r2 ≈ | 4 | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 16 | |
| v ≈ | 1.1 | 1.1 | 1.3 | 1.6 | 1.9 | 2 | 2.5 | 3 | 3.7 | |
| Z | recess nr | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 3 | 4 |
| m ≈ | 2.11 | 2.11 | 2.9 | 3.15 | 3.91 | 4.29 | 4.7 | 6.73 | 8.46 | |
| max depth | 1.42 | 1.42 | 1.78 | 2.06 | 1.93 | 2.34 | 2.74 | 3.48 | 4.17 | |
| min depth | 1.17 | 1.17 | 1.53 | 1.81 | 1.47 | 1.88 | 2.28 | 3.02 | 3.71 | |
| H | recess nr | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 3 | 4 |
| m ≈ | 2.5 | 2.5 | 2.7 | 3.1 | 4.2 | 4.6 | 5.3 | 6.8 | 9 | |
| max depth | 1.4 | 1.4 | 1.6 | 2 | 2.24 | 2.54 | 3.27 | 3.53 | 4.88 | |
| min depth | 1.1 | 1.1 | 1.3 | 1.7 | 1.74 | 2.04 | 2.77 | 3.05 | 4.18 | |
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Uni 8112 ≈ commercial items |
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| d thread size | M 2 | M 2.2 | M 2.5 | M 3 | M 3.5 | M 4 | M 5 | M 6 | M 8 |
| nominal length l | |||||||||
| 4 | X | X | X | ||||||
| 5 | X | X | X | X | |||||
| 6 | X | X | X | X | X | X | |||
| 8 | X | X | X | X | X | X | X | ||
| 10 | X | X | X | X | X | X | X | X | X |
| 12 | X | X | X | X | X | X | X | X | X |
| 14 | X | X | X | X | X | X | X | X | X |
| 16 | X | X | X | X | X | X | X | X | X |
| 20 | X | X | X | X | X | X | X | ||
| 25 | X | X | X | X | X | X | X | ||
| 30 | X | X | X | X | X | X | X | ||
| 35 | X | X | X | X | |||||
| 40 | X | X | X | ||||||
| 45 | X | X | X | ||||||
| 50 | X | X | X | ||||||