Routing Basics

Jan. 15, 2004
By Gale Johnson and Jerry Levine

Installing non-cylindrical lock hardware requires varying configurations for the door face and edge openings, as well as the jamb openings. For many years, locksmiths would use drills, jig saws, files (metal/aluminum) and chisels (wood) to prepare the openings for lock hardware.

With the introduction of the router and router templates, preparing the door and jamb for lock hardware has been simplified, becoming a definite time saver. Another important advantage is the router and template will cut a consistent-sized opening.

The downside is the cost of the router and the templates. A good quality router will cost approximately $200. The cost of templates varies depending upon manufacturer, materials and application. Lock hardware templates are manufactured of aluminum or plastic, usually with hardened inserts at critical locations. Most templates are designed for a specific lock manufacturer's product. However, once you decide upon a specific make and model of lock hardware, the initial cost of the template decreases by the number of installations. Using a router and templates in the end will save a significant amount of time, money, and minimize the possibility of damaged doors.

Suggestion: Before purchasing a router, contact the manufacturer of the templates and ask their recommendations for a brand and model.

There are two types of routers: the plunge router and the fixed-base router. The plunge router is designed to cut to a varying degree of depth in wood without having to stop and re-adjust the depth of cut. The plunge router is mainly used for wood applications where the opening is routed through solid material. Some plunge-type routers have an auto-zero that makes it easier to adjust the depth of plunge.

The fixed-base router is designed to be set to a particular depth of cut. If the material requires several passes, then the depth of cut has to be reset after each pass.

In basic terms, the more power a router has, the better for cutting harder materials, larger diameter cutters and cleaner cuts. Power also usually dictates the size and weight of the router. Remember, the more horsepower, the heavier the router and the more difficult it can be to operate.

Many routers offer variable speed motors. The speed required will depend upon the size of cutter and the material being cut. Some routers have a fixed speed. Routers can operate at a range from about 8,000 to 28,000 rpm. Fixed-speed routers operate at a speed usually in excess of 20,000 rpm. All speeds are determined at no-load. The smaller the motor's horsepower, the greater speed is required because much of the speed will be lost when the cutter contacts the working surface.

Important: For adjustable or variable speed routers, the appropriate speed setting for the cutter and the material being cut will usually be determined by trial and error.

Collet Size
The collet holds the cutting tool. The size of the collet determines the size of cutter shank. Routers are available with a collet size of 1/4 and 1/2 inch diameter. Collet size is usually determined by the power of the machine. Light-duty routers will usually have a 1/4-inch diameter collet, where heavy-duty routers will usually have a 1/2-inch diameter collet. Smaller diameter collets will only be able to use smaller diameter cutters. However, there is an advantage for the larger routers. Quarter-inch collet reducers are available for routers equipped with 1/2-inch diameter collets.

Template Guides
A template guide fits under the router's base plate and projects a sleeve downwards. The sleeve is slightly larger than the diameter of the cutter. The outside of the sleeve is used to guide the router around a template.

When purchasing template guides, make sure they are manufactured of machine steel or brass. This way, they will not rust or harm your cutter if hit. Machine steel and brass are softer than tool steel. Each router manufacturer uses its own style of template guide. Template guides are sold individually or in multi-piece kits.

Note: Use a 3/8" O.D. template guide for a 1/4" diameter router cutter. Use a 5/8" O.D. template guide for a 1/2" diameter router cutter.

When purchasing a plunge router, it is recommended that the "On/Off" switch, speed control and the plunge adjustment be located adjacent to the handles. This way, the router functions can be changed without removing your hands from the handles. You do not want the controls located where they could be changed accidentally. Test each model for control and comfort.

Router cutters are designed for specific applications. There are wood cutters, aluminum cutters, and metal cutters. For most applications, locksmiths will route openings through solid wood and varying thicknesses of aluminum. Contact the template manufacturer, and use the cutters they recommend. This will ensure the best possible results.

For example, the Major Manufacturing HIT-45RB4 1/4"-diameter down shear router cutter is designed for routing aluminum. The down shear cutter moves the cuttings down. This cutter does not throw cuttings up towards the router, instead it throws cuttings downward, away from the router.

Before using a router, check:

  • To make sure the cutting edges are sharp. If not replace or re-sharpen.
  • To make sure the shank is straight. Bent shanks can cause the cutter to run "out of true".
  • To make sure the cutter is clean. Remove all trace of glue, resin, sawdust etc.

Router Cutter Installation
Always insert at least three-quarters of the cutter shank into the collet and securely tighten. If not, when operating, the cutter may flex excessively, resulting in a poor edge or even worse, the cutter coming out of the collet.

Suggestion: When routing an opening into metal or aluminum, dip the router cutter into the tapping fluid or use a small brush to coat the cutter. In addition, brush the tapping fluid onto the metal or aluminum surface being cut. Tapping fluid reduces the friction, keeping the cutter cooler and extending its life. Router cutter tapping fluid can be purchased at most hardware stores. Read the label for the proper tapping fluid for the material being cut.

A tip: When setting the depth for routing a strike plate, place two strike plates onto a flat surface. Place the template onto the two strike plates. Place the router onto the template. Lower the cutter until the tip just touches the surface the two strike plates are resting on. This sets the exact depth for the router cutter to cut a clean strike plate opening into a wooden jamb.

Here are some basic rules to follow:

  • Wear ear and eye protection.
  • Unplug the router before making any adjustments.
  • Cut in a clockwise direction.
  • Adjust the cutter so only 1/8" to 1/4" extends beyond the metal or aluminum lower cutting surface.
  • Feeding the router too fast or with too much cutting depth can splinter the wood. Wood will show burn marks.
  • Use multiple passes for depths of cut greater than 1/4" especially in hard woods.
  • Never reverse direction when operating a router. You can always make a second pass over the area.
  • Wait until the cutter stops turning completely before removing the router from the template.
  • Make a second pass to ensure a clean installation.
  • Check the opening. Use a brush or rag to remove any chips or debris from the opening.
  • Use a coarse, flat bastard file to square the frame corners to accommodate the strike lip.

Operating The Router
The secret to successful routing is selecting the proper rate-of-feed. Clean, smooth routing is the result of cleanly removing small amounts of material with the cutter rotating at a fast speed.

If the cutter is forced to travel too fast, the speed will slow, and larger amounts of material will be removed. The result is a rougher finished or damaged product, with the possibilities of dulling or damaging the cutter. A too fast rate-of-speed will produce a slowing of the motor, and the material cut will become bigger and bigger.

If the cutter is forced to travel too slow, it may not create a continuous pattern of cuts. Instead, the cutter may scrape away along the edge of the material. Scraping produces heat, which can damage the material and the cutter. In addition, moving the router too slow makes it more difficult to control. A too slow rate-of-feed can be heard and felt. The motor will have a very high pitched sound, and the router will jolt between cuts.

At the proper rate-of-feed for the router, cutter, and material, the motor will maintain a constant speed, the material removed will remain a uniform chip size, and the router will slide smoothly across the work surface.

Note: Routers are not designed to create square corners. If the lock hardware being installed requires squared corners, use a chisel, file or corner punch to create the square corner.

Routers normally need little maintenance. Keep the air vent holes of the motor unobstructed to prevent the motor from overheating. Keep sawdust away from the inside of the motor; sparks from the motor can ignite the dust.

As a final suggestion, always check the operation of the door when doing an on-site estimate. If the door does not properly operate, then repairs must be made prior to any other work. The door must be properly aligned within the opening. Does the closer close and latch the door? If not, inspect the door to determine what hardware items must be repaired or replaced. Always quote repair of the door or frame separately. This way your customer will know the actual costs for each job.

For more information on routers, contact your local hardware store or locksmith wholesaler. For more information on router templates, contact your local locksmith wholesaler. A partial list of manufacturers includes:
  • A-1 Security Manufacturing Corp., 3001 West Moore, Richmond, VA 23230. Telephone: 804-359-9003. Fax: 804-359-9415. Website: .
  • Major Manufacturing, Inc., 1825 Via Burton, Anaheim, CA 92806. Telephone: 714-772-5202. Fax: 714-772-2302. Website: .
  • Pro-Lok®, 655 North Hariton Street, Orange, CA 92868-1311. Telephone: 714-633-0681. Fax: 714-633-0470. Website: .
  • Security Lock Distributors, 40A Street, Needham Heights, MA 02494. Telephone: 781-444-1155. Fax: 781-444-1155. Website: .




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