Table of Contents

What is Production Drawing | Need , Elements Of Production Drawing

What is Production Drawing

Producing Drawing A component or part drawing is termed as a production drawing, if it facilities its manufacture. It is an authorized document to produce the component in the shop floor. It furnishes all dimensions, limits and special finishing processes such as heat treatment, grinding, etc., in addition to the material used. It should also mention the number of parts that are required for making of the assembled unit, of which the part is a member.

Production drawing of a component should also indicate the sub or main assembly where it will be assembled. It is necessary to prepare the production drawing of each component on a separate sheet, since a craftsman will ordinarily make one component at a time. However, in some cases, the drawings of related components may also appear on the same sheet. Figure shows the production drawing of a jig bush.

Need for a production drawing

The graphic representation of a product, starts at the transformation stage of ideas into a drawing by a design engineer. A production drawing is a complete working drawing, representing all the details of the product, regarding size, shape, material, process, tools and equipment. The craftsman is completely guided by the production drawing, during the manufacture of the product. Hence, any mistake in a production drawing will result in loss of time, money and decreased productivity. Further, it is a legal document while going for subcontracting of works. Hence, a production drawing should be prepared without any scope for more than one interpretation.

The design engineer uses orthographic or pictorial views to record his ideas, free hand. These are called working sketches. These sketches are used for both the component and assembly drawings. The working drawings are sent to the shop, in the form of blue prints, ammonia prints or other similar forms of reproduction. Therefore, the drawings must be made as tracings.

Elements of production drawing

Following are the basic elements of a production drawing.
1. Format of drawing sheet,
2. Size and shape of the component,
3. Projection method,
4. Material specification and shape such as castings, forgings, plates, rounds, etc.,
5. Indication of surface roughness and other heat treatments, if any,
6. Limits, fits and tolerances of size, form, and position,
7. Production method,
8. Process sheet,
9. Specification of standard components,
10. Conventions used to represent certain machine components, and
11. Inspection and testing methods.