Production Broaching
The term “production broaching” refers to broaching services performed in large quantities in order to create precise and uniform results of a large product order. Broaching is a machining process used to shape material, mainly metal material, into something new via cutting. The process uses a tool called a broach, which removes unwanted or excess material to a number of different effects related to texture, shape, size, and depth.
Quick links to Production Broaching Information
Equipment Used in Production Broaching
Broaching tools are toothed and similar to saws, though they are generally much smaller and their teeth increase in height as they extend along the tool. The difference between advancing tooth heights is known as the rise per tooth (RPT), or step or feed per tooth. The RPT determines the amount of metal material removed during a production broaching run, and the size of the chip that follows. Broaching tools are also divided into three sections: the first is for roughening, the second is for semi-finishing, and the third is for finishing. Because they consist of a minimum of two cutting edges, they can be categorized as multiple point cutting tools. In order to complete the broaching process, workers may use additional tools, such as broach horns, which physically support the broach. Manufacturers can undertake production broaching using standard tools and machines or custom-built equipment. By using standard broaching tools, manufacturers can keep their costs down without compromising quality. However, if they use custom-made tools, they will be able to create products that adhere to their exact specifications.
Types of Broaching
Standard and semi-standard broach types are categorized by function, use, purpose, construction, or motion. The two broad categories they are most often divided into are “surface” and “internal”. Production broaching done with surface broaches cuts materials on a surface level, while production broaching done with internal broaches cuts materials more deeply. Surface broaches are subdivided into slab broaches, slot broaches, contour broaches, pot broaches, and saddle broaches. Likewise, types of internal broaches include solid broaches, shell broaches, modular broaches, and cut-and-recut broaches.
Slab broaching and slot broaching are both widely used in production broaching, since they both can yield high volume results. Slab broaches are general purpose tools used to cut into flat surfaces, while slot broaches are tools that cut slots of varying dimensions into surfaces at high production rates. Contour broaches, as their name implies, are designed to service contoured, convex, cam, and irregularly shaped surfaces. Pot broaches are named after the fixture in which they are mounted, which looks like a pot. This pot holds multiple broaching tools concentrically over its entire length. Pot broaches stand still as a cylindrical workpiece is pulled or pushed through them so that it can be cut on the outside. Pot broach fabrication has largely replaced the production of hobbing machines for use with external spline and slot cutting and involute gears. The last of the surface broaches used in production broaching are straddle broaches. Using two slab broaches, straddle broaches cut parallel surfaces on opposite sides of a workpiece. Saddle broaches hold closer tolerances than independent cutting broaches known to make lovely cuts in just one pass.
Production broaching relies on internal broaches to cut materials beyond, or through, their surface. Of all the internal broaches, in production broaching, solid broaches are used the most. Solid broaches are simply constructed from one solid piece of material. In contrast, the next type of broach, shell broaches, have a hole in the center where they can be mounted upon an arbor. Because they are easier to produce and reproduce, shell broaches are used in production broaching settings that require frequent broach replacement. Next, modular broaches are typically used for the largest of production broaching applications. Thanks to their multiple piece construction, they offer greater flexibility, easier resharpening, and more economical fabrication than others. Lastly, cut-and-recut broaches are used to cut thin-walled objects. They cut these objects in a three-part method that overcomes their tendency to expand during cutting and shrink afterward.
Factors to Consider When Using Production Broaching
Production broaching is a somewhat expensive procedure but mainly in the production of the broaches themselves. A well-made broach or broaching machine will yield high-end products and, when used to produce a high enough volume of them, the money invested to make the broaching equipment will quickly return. To find out if production broaching is the right way for you to go, contact one of our knowledgeable and experienced broaching manufacturers today.