What is Representative Factor (R.F.)?

Definition of Representative Factor

Representative Factor or Representative Fraction (R.F.) is defined as ratio of size or dimension of element or part in drawing to the size of same element or part of the actual object.

Representative Factor (R.F.)

Dimension in Drawing / (Actual) Dimension of Object

= Length or Width or Height in Drawing / (Actual) Length or Width or Height of Object

For FULL SIZE SCALE* R.F.=1  OR   ( 1:1 ) Means Drawing & Object are of Same Size.

* There are mainly three types of scales (1) Full Scale (2) Reduced Scale (3) Enlarged Scale

(1) Full Scale:

Using Full scale means you are drawing object’s all lines and points as per in drawing data. If we study it further, Drawing is in Full Scale if dimensions in data and the dimensions in drawing are same. Let us take and example: One circle’s radius is 20 mm in data and you are drawing it of 20 mm in drawing then you are using full scale in drawing.

Example: 1:1, 2:2, 3:3, 4:4, 5:5 etc.

(2) Reduced Scale:

Using Reduced scale means you are drawing object’s all lines and points by reducing it to some points. Let us take an example: One circle’s radius is 20 mm in data but you are drawing it of 10 mm in drawing then you are using reduced scale in drawing.

Example: 1:2, 1:3, 1:4, 1:5, 1:6 etc.

(3) Enlarged Scale:

Using Enlarged scale means you are drawing object’s all lines and points by increasing or enlarging it to some points. Let us take an example: One circle’s radius is 20 mm in data but you are drawing it of 40 mm in drawing then you are using enlarged scale in drawing.

Example: 2:1, 3:1, 4:1, 5:1, 6:1 etc

Author: Vasim Machhar

An Engineering Drawing Geek. Working at Noble Group of Institutions, Junagadh as Head of Mechanical Engineering Department.