Threaded fasteners refer to the main and auxiliary parts that are tightened and connected by screws.
Commonly used fasteners are bolts, screws, studs, nuts, and washers, all of which are standard parts. When designing a machine, the standard part does not have to draw a part drawing, just draw it in the assembly drawing and write the mark of the standard part used.
First, the drawing method of commonly used threaded fasteners.
The dimensions of the various parts of the fastener can be found from the corresponding national standards, but for the sake of simplicity and efficiency in a drawing, most of them do not have to look at the drawing but use the scale drawing method.
The so-called scale drawing method is that when the thread diameter is selected, the effective length of the threaded fastener is determined according to the actual condition of the fastener, and the other parts of the fastener are taken to the thread diameter of the fastener. d is a method of drawing a certain proportion of values.
In general, fasteners are simplified and the principles are simplified as follows:
1. The category, the standard chronograph number and the preceding "-" are allowed to be omitted in whole or in part. The standard for omitting the age number shall be based on the current standard.
2. The "-" in the mark allows all or part of it to be omitted; the "x" before the "other diameters or characteristics" in the mark allows the thumbnail. However, omission should not lead to misunderstanding of the mark, usually replaced by a space.
3. When only one product form, performance grade or hardness or material, product grade, wrenching form and surface treatment are specified in the product standard, all or part of it is omitted.
4. When two or more product forms, performance grades or hardnesses or materials, product grades, wrenching forms and surface treatments are specified in the product standard, one of which may be omitted and marked in the product standard. The simplified markup omitted is given.