Standard Terminology for Describing Timbers

It is found that lack of recognized conventions in the use of proper adjectives for describing the properties of timbers often leads to confusion. For instance, in giving the weightiness of a timber, the adjective "heavy" has been used to denote the weight per cubic ft. of seasoned timber for various magnitudes such as 50 to 60 lbs. in one case, 39 to 49 lbs. in another, 40 to 49 lbs. in the third and 42 to 49lbs. in the fourth case by different authors. Similarly in telling the hardness of a timber, writers use the feel they experience in cutting it by a pen-knife. This feel depends upon the sharpness of the knife, the hardness of the steel of which it is made, the moisture content of the timber and above all, the personal factor of the writer. An attempt is made in this article to standardize the meanings of various descriptive adjectives by giving them as far as possible, some definite quantitative interpretations in order to avoid the state of confusion that exists, and ensure uniformity. Teak has been taken as the standard of comparison of all our timbers, as it is the most widely used and well-known timber, and the physical and mechanical properties of all other timbers are compared with those of teak by specially prepared comparative suitability index figures which have already been published. Indian species have been classified in this article according to their characteristics of weight, strength as a beam, hardness, shock resisting ability and retention of shape. Description of five species is given at the end as an example of the use of the proposed terminology.