Slotting machining is a milling process in which a mill is used to cut a narrow ridge into a workpiece surface. Slotting machines have a stationary cutting tool and a moving table so that a metal or wooden workpiece can be moved for slotting. The proper selection of a slotting machine requires a careful analysis of product types. Metal-cutting slotters can create flat surfaces as well as T-slots, curved surfaces and dovetails. Profilers follow a wooden template, pantographs use a plug for tracing the path and computer numerical control (CNC) machines use a computer program to generate the path.

A slotting machine is used to cut a slot or groove in a hole. When cutting splines (multiple grooves) however, a broaching machine is often used instead. With various attachments, milling machines can also be used for slotting (by attaching the proper slotting tooling), drilling and so on. Consider the following when looking to purchase slotting machines:

1. Buy metal slotting machines for cutting grooves in metal workpieces.

2. Acquire a wood cutting slotter.

3. Order slotting services to be performed by experienced machinists.

Action Steps
The best contacts and resources to help you get it done

Select a slotting machine for metalwork

If you're looking to buy a metal working slotting machine, remember there are different varieties,depending on what you're working with. There are slotters for working on flat steel, ones for working on flat aluminum and ones for working on piping. When shopping for tooling bits for slotting, information will be required to select the right part such as cutting diameter, standard hole, standard kerf and the number of wings.

I recommend: Sandvik Coromant sells slot milling equipment. Under "Products," select "Milling" and then "Slot Milling." J&K Tool carries pipe slotting equipment.

Find the right slotter for your woodworking tasks

In construction, where steel plates are to be inserted into timber, a chain slotter is the perfect tool for creating straight vertical slots. A slot is cut by plunging the machine's bar/chain along its guide stand, either with or across the grain, into the wood.

I recommend: MLS Machinery sells a 12 ft. slot former machine. Timber Frame Tools carries a line of chain slotters, designed for use by carpenters and timber framers.

Find slotting service providers to do the work for you and free up your staff for other work

Outsourcing the work is always an option if you don't have the necessary equipment for a particular job or experienced personnel to slot the pieces to specifications.

I recommend: VW Broaching Service offers a full gamut of machinist services, including slotting. Creare offers specialized machining services, including slotting.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Although the slotting machine has the disadvantages of an arm unsupported beyond the guides in which it moves and a non-productive return stroke, the ability of the table to make compound movements enables the slotting machine to produce shapes that cannot be achieved on planers and shapers, like circular parts and circular arcs combined with straight sections.