Cutting Splines

• Cutting Tools

Click image to enlargeNeed to make a million gears?

You might want to give Brett Froats a call. He’s the president of the broaching division at Colonial Tool Group Inc., and says his company is the only full-service provider in Canada, engineering, building, and servicing a complete line of broach tooling and equipment. 

“Many of our customers are Tier One automotive providers–companies like Linamar, and Magna, that need to produce high volume transmission parts, for example, rack and pinion steering or powertrain components,” he says. “Once you get upwards of, say, half a million or so parts, broaching is far more cost effective than hobbing or shaping. It’s really the fastest, most economical, and accurate way of metal removal for internal and external splines, keyways, dovetails, and many gear forms.”

Click image to enlargeThe tooling used to cut these shapes is usually made of high speed steel, with or without various coatings based on the application. And the machines aren't super expensive, at least by automotive standards–an automated turnkey broach starts just under $250,000 (plus options), too much by far for occasional use but easily justifiable if you can keep it busy. If you’re interested in extending your shop’s capabilities, Froats says broaching is used in non-automotive applications as well, such as fir-tree profiles in turbine discs for aircraft engines. In these cases, dedicated six axis broaches with up to 7 m or more (23 ft.) of horizontal travel is sometimes required, machines that cost far more than the figure just mentioned. If you’d rather just stick to general machining, Colonial offers contract broaching services to those customers with intermittent needs, or for those still ramping up to higher, “let’s bring it in house” part volumes.