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In order to reduce the risk of the round head phillips machine screw during assembly, the thickness of the plating layer is strictly controlled during the surface treatment to ensure that the screw fasteners after plating do not exceed the customer’s tolerance.
Table 1 Coating Thickness (unit:μm)
| Nominal plating thickness | Effective coating thickness | ||
| Local thickness min | Batch average thickness | ||
| min | max | ||
| 3 | 3 | 3 | 5 |
| 5 | 5 | 4 | 6 |
| 8 | 8 | 7 | 10 |
| 10 | 10 | 9 | 12 |
| 12 | 12 | 11 | 15 |
| 15 | 15 | 14 | 18 |
| 20 | 20 | 18 | 23 |
| 25 | 25 | 23 | 28 |
| 30 | 30 | 27 | 35 |
If the nominal length of the round head phillips machine screw is l>5d, when measuring the average thickness of the batch, the thickness of the coating should be less than the tolerance specified in Table 1, see Table 2.
Table 2 Upper Deviation Value Of Ordinary Thread Plating Thickness
| Thread P/mm | Coarse thread nominal diameter d/mm | External thread | ||||||||||||||
| Tolerance zone position g | Tolerance zone position f | Tolerance zone position e | ||||||||||||||
| Basic deviation /μm | Coating thickness/μm max | Basic deviation /μm | Coating thickness/μm max | Basic deviation /μm | Coating thickness/μm max | |||||||||||
| 1) | 2) | 1) | 2) | 1) | 2) | |||||||||||
| All nominal length | Nominal length l/mm | All nominal length | Nominal length l/mm | All nominal length | Nominal length l/mm | |||||||||||
| L≤5d | 5d＜l≤10d | 10d＜l≤15d | L≤5d | 5d＜l≤10d | 10d＜l≤15d | L≤5d | 5d＜l≤10d | 10d＜l≤15d | ||||||||
| 0.2 | 1
1.2 |
-17 | 3 | 3 | 3 | 3 | ||||||||||
| 0.25 | 1
1.2 1.4 |
-18 | 3 | 3 | 3 | 3 | ||||||||||
| 0.3 | 1.4 | -18 | 3 | 3 | 3 | 3 | ||||||||||
| 0.35 | 1.6
1.8 |
-19 | 3 | 3 | 3 | 3 | -34 | 8 | 8 | 5 | 5 | |||||
| 0.4 | 2 | -19 | 3 | 3 | 3 | 3 | -34 | 8 | 8 | 5 | 5 | |||||
| 0.45 | 2.2
2.5 |
-20 | 5 | 5 | 3 | 3 | -35 | 8 | 8 | 5 | 5 | |||||
| 0.5 | 3 | -20 | 5 | 5 | 3 | 3 | -36 | 8 | 8 | 5 | 5 | -50 | 12 | 12 | 10 | 8 |
| 0.6 | 3.5 | -21 | 5 | 5 | 3 | 3 | -36 | 8 | 8 | 5 | 5 | -53 | 12 | 12 | 10 | 8 |
| 0.7 | 4 | -22 | 5 | 5 | 3 | 3 | -38 | 8 | 8 | 5 | 5 | -56 | 12 | 12 | 10 | 8 |
| 0.75 | 4.5 | -22 | 5 | 5 | 3 | 3 | -38 | 8 | 8 | 5 | 5 | -56 | 12 | 12 | 10 | 8 |
| 0.8 | 5 | -24 | 5 | 5 | 3 | 3 | -38 | 8 | 8 | 5 | 5 | -60 | 15 | 15 | 12 | 10 |
| 1 | 6
7 |
-26 | 5 | 5 | 3 | 3 | -40 | 10 | 10 | 8 | 5 | -60 | 15 | 15 | 12 | 10 |
| 1.25 | 8 | -28 | 5 | 5 | 3 | 3 | -42 | 10 | 10 | 8 | 5 | -63 | 15 | 15 | 12 | 10 |
| 1.5 | 10 | -32 | 8 | 8 | 5 | 5 | -45 | 10 | 10 | 8 | 5 | -67 | 15 | 15 | 12 | 10 |
| 1.75 | 12 | -34 | 8 | 8 | 5 | 5 | -48 | 12 | 12 | 8 | 8 | -71 | 15 | 15 | 12 | 10 |
Note: 1) The maximum thickness of the coating when measuring the local thickness
2) The maximum thickness of the coating when measuring the average thickness of the batch
The coarse pitch information provided is only for convenience, and the pitch is determined.
If you want to customized round head phillips machine screw please send an email: annie.li@szsst88.com
12 月-30-2018
kalyn
+86 13143444311
sst@szsst88.com
