Which of the following defects occurs when a small depression is formed on the finished surface of timber by falling of a tool?

Explanation:

Defects due to conversion:

Chip mark: 

• This defect is indicated by the marks or signs placed by chips on the finished surface of timber. They may also be formed by the parts of a planing machine.

Diagonal grain:

• This defect is formed due to improper sawing of timber. It is indicated by diagonal mark on straight grained surface of the timber.

Torn grain: 

• This defect is caused when a small depression is formed on the finished surface of timber by falling off a tool or so.

Wane: 

• This defect is denoted by the presence of an original rounded surface on the manufactured piece of timber.