Sentence:  When checking <WSD>sprags</WSD>, anvil and spindle ends of micrometer and flat back of <WSD>sprag</WSD> must all rest on a flat surface as shown in view A. / Since wear on all <WSD>sprags</WSD> in any one <WSD>sprag</WSD> unit will be the same, it is only necessary to check 5 <WSD>sprags</WSD> in each assembly. 
Meaning of the word marked with <WSD> tags:  A billet of wood; a piece of timber, a similar solid object or constructed unit used as a prop.