Chapter 4: Process Side Effects

OVERVIEW

Mass finishing has several side effects, which users must note before they employ any processes. Many of these side effects are beneficial, but some are not. Our list of essential mass finishing rules continues with this point about side effects:

Rule #6: In addition to removing burrs and improving surface finishes, mass finishing at the same time changes other key attributes of parts, some for the worse and others for the better.

In addition to removing burrs, mass finishing can:

• radius or blunt part edges

• change part dimensions (0.000050 in.-0.003 in.)

• change a part's surface finish

• compact a part's surface "pores"

• clean a part's oily and dirty surfaces

• remove oxides and heavy scale from a part

• change a part's flatness

• prevent electroplating adhesion (if wrong media is used)

• prevent soldering (if the wrong abrasives are used)

• cause blowholes in welded joints (if wrong abrasives are used)

• create large compressive stresses on a part

• cause dings, scratches, and dents to a part

• improve or worsens corrosion rates

• change part luster

• change part color

• change friction

• decontaminate radioactive surfaces

Impacts of these changes are presented in Table 4-1 in a format that manufacturing staffs can use to ask customers, "Do unique requirements exist that are not stated on the drawing?" This table is included because designers cannot know the impact that the listed changes can have on a design if they do not know about the process used. When a customer has a finishing requirement, Table 4-1 should be completed and...