1. ASSEMBLY

 

• the mating of parts to give a combined operation.

 

• In previous centuries, and before, fit in assemblies was often not considered, or when it did matter, each piece was custom fitted.

 

• Modern methods of mass production means that some fundamental methods of fitting are necessary.

 

• The three basic methods of fitting are,

- Fitting - One part is made to size, and then a second part is made to fit it.

- Selective Assembly - parts are made to loose general tolerances, and then the results are sorted into tolerance ranges. (e.g. bearings, solar cells, etc)

- Interchangeable Assembly - Parts are made to tighter tolerances, and as a result assembly of randomly selected parts will yield a good fit. This is essential for modern assembly lines.

 

• The basic categories of fits are,

- Clearance - a gap is always present between parts

- Transitional - the parts will have a gap sometimes, other times the parts will touch

- Interference - both parts will always be in full contact

 

 

1.1 THE BASICS OF FITS

1.2 C.S.A. B97-1 1963 LIMITS AND FITS(REWORK)

1.3 CSA MODIFIED FITS

1.4 CSA LIMITS AND FITS

1.5 THE I.S.O. SYSTEM

1.6 PRACTICE PROBLEMS