How do you see the drawing of the extra long screws?

When some customers are customizing extra long screws, they only know the size they need, but they can’t understand the drawings made according to the size. Then the screws produced by the manufacturer according to the drawings are actually assembled by the customer. Will find out what went wrong. So how do you look at the screw drawings?

Take this drawing as an example.

The information we can see from the drawing is that the size of the screw is M5*260, hexagon head half thread machine screw. The opposite side of the outer hexagon is 9mm, the allowable tolerance is +0.2mm/-0.2mm, ie 8.8mm-9.2mm, the head thickness is 5mm, and the tolerance is +0.15mm/-0.15mm, ie 4.85mm-5.15mm, rod The diameter of the part is 4.7mm-5.0mm, the thread length is 30mm, the tolerance is +2mm/-2mm, which is 28mm-32mm, and the screw length tolerance is +1mm/-1mm, which is 259mm-261mm.

Although the thread of the extra long screws is M5, it does not mean that the thread is 5mm. M5 is just a standard. In fact, the thread diameter is 4.83mm-4.98mm. If there is no special mark, it generally refers to the coarse thread. The thread diameter range of the coarse thread is this size, and the pitch of the coarse thread is 0.8mm.

If the customer marked M5*0.5-6G on the threaded part, it means that the pitch is 0.5mm, and the 6G pass gauge is used, and the thread diameter range is 4.874mm-4.98mm. Will you read the drawings of the extra long screws now?