The Problem with Minimizing Burrs on Manufactured Parts
The generally-accepted definition of burrs is a protruding ragged ridge or area of roughness produced in the cutting, shaping, drilling, or shearing of metal products.
Deburring is a process meant to affect a specific outcome that is kept rigidly within a pre-determined set of edge standards. These standards may vary from one manufacturing plant to another, one country to another – but since the dawn of modern metal parts manufacturing there has always been a general understanding of allowable edge conditions. What constitutes “burr free” is largely dependent on the needs of the manufacturer. As a company of experienced designers and manufacturers of deburring equipment, we’ve seen manufacturing standards that are based on what can be seen by the un-aided human eye, to those held to the strictest of standards involving the mitigation of functional problems in assembly and total product quality inspections.
It is generally understood that burrs and sharp edges cause problems for the manufacturing industry. Edge quality has always been seen as a concern for the end-performance and appearance of the finished product. There are a number of processes that affect minimizing or eliminating burrs in the manufacturing environment. Some of these processes are focused on product design. Some concern tool design. Others minimize burrs through process design.
Note: Some deburring processes are implemented because they involve health and safety concerns (sometimes environmental concerns are also part of the mix), but this is something that can be discussed in another article.
The difficulties created by burrs vary with each unique manufacturing process and product. Burr properties (location, thickness, shape, roughness) are also unique to the manufacturing situation. A complete list of difficulties and problems involving the build-up of burrs on gears and sprockets – as they relate to the edge quality of finished products – would be too lengthy to list here. As an example, a shortened list of the more common problems include edge fitting interference in product assembly, mechanism jamming along the assembly line, increased wear on parts, improper seals where edges meet, and safety concerns involving cuts and bruises for workers along the line.
The problem with minimizing burrs on manufactured parts is that the only true way to minimize the presence and effects of burrs is to form your parts or cast your edges instead of machining them. In a high percentage of manufacturing situations, this is simply not applicable to the needs of the end product. Some nontraditional machining processes (those that utilize chemicals, super-high-speed machining, and sacrificial back-up material) may be a viable option in certain manufacturing circumstances. It should be stated that non-traditional machining methods – although they may reduce the presence and effects of burrs with end-products – may still produce an unwanted amount of other variances in finished edge material.