This product guide contains the specification for metric threaded dog point grub screws available from Westfield Fasteners. The basis of this specification is the ISO standard ISO 4028 and the older DIN 915.
Grub screws in general are graded by hardness rather than by tensile strength. The relevant DIN and ISO standards specify a 45H hardness grade for non stainless steel grub screws and 21H for stainless steel grub screws.
Although the DIN 915 standard has been superceded by ISO 4028, the dimensions are the same and off-the-shelf parts could be marked with either standard.
Thread, d | M1.6 | M2 | M2.5 | M3 | M4 | M5 | M6 | M8 | M10 | M12 | M16 | M20 | M24 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
thread pitch (standard metric coarse) | 0.35 | 0.4 | 0.45 | 0.5 | 0.7 | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 | |
diameter of dog point | dp max. | 0.80 | 1.00 | 1.50 | 2.00 | 2.50 | 3.50 | 4.00 | 5.50 | 7.00 | 8.50 | 12.00 | 15.00 | 18.00 |
dp min. | 0.55 | 0.75 | 1.25 | 1.75 | 2.25 | 3.2 | 3.7 | 5.2 | 6.64 | 8.14 | 11.57 | 14.57 | 17.57 | |
diameter of the face | df | ≈ (approx.) Minor thread diameter | ||||||||||||
socket width across corners | e min. | 0.809 | 1.011 | 1.454 | 1.733 | 2.303 | 2.873 | 3.443 | 4.583 | 5.723 | 6.863 | 9.149 | 11.429 | 13.716 |
socket width across flats | s nom. | 0.7 | 0.9 | 1.3 | 1.5 | 2 | 2.5 | 3 | 4 | 5 | 6 | 8 | 10 | 12 |
s max. | 0.724 | 0.913 | 1.300 | 1.580 | 2.080 | 2.580 | 3.080 | 4.095 | 5.140 | 6.140 | 8.175 | 10.175 | 12.212 | |
s min. | 0.710 | 0.887 | 1.275 | 1.520 | 2.020 | 2.520 | 3.020 | 4.202 | 5.020 | 6.020 | 8.025 | 10.025 | 12.032 | |
socket depth | t min. (shortest lengths) | 0.7 | 0.8 | 1.2 | 1.2 | 1.5 | 2 | 2 | 3 | 4 | 4.8 | 6.4 | 8 | 10 |
t min. (other lengths) | 1.5 | 1.7 | 2 | 2 | 2.5 | 3 | 3.5 | 5 | 6 | 8 | 10 | 12 | 15 | |
length of dog point (shortest screw lengths) | z max. | 0.65 | 0.75 | 0.88 | 1.00 | 1.25 | 1.50 | 1.75 | 2.25 | 2.75 | 3.25 | 4.30 | 5.30 | 6.30 |
z min. | 0.40 | 0.50 | 0.63 | 0.75 | 1.00 | 1.25 | 1.50 | 2.00 | 2.50 | 3.00 | 4.00 | 5.00 | 6.00 | |
length of dog point (other screw lengths) | z max. | 1.05 | 1.25 | 1.50 | 1.75 | 2.25 | 2.75 | 3.25 | 4.30 | 5.30 | 6.30 | 8.36 | 10.36 | 12.43 |
z min. | 0.80 | 1.00 | 1.25 | 1.50 | 2.00 | 2.50 | 3.00 | 4.00 | 5.00 | 6.00 | 8.00 | 10.00 | 12.00 |
thread length (mm) | +/- (mm) |
---|---|
2-3 | 0.2 |
4-6 | 0.24 |
8-10 | 0.29 |
12-16 | 0.35 |
20-30 | 0.42 |
35-50 | 0.5 |
55-60 | 0.6 |