Selecting a bearing-guided router bit for plywood edges

A router bit with a bearing can make plywood edging quicker, cleaner and easier to control. The bearing follows the workpiece or a template while the cutter trims the overhanging veneer, rounds an exposed edge or creates a small decorative profile. For scroll saw projects, shelves, boxes and craft furniture, the right bit can give a crisp result without extensive hand sanding.

Plywood does require some care. Its face veneer is thin, its glue layers can be abrasive, and the exposed edge may chip as the cutter exits. Australian makers also need to check shank sizes, timber availability and workshop conditions before buying. A bit that performs beautifully in a dry garage in Melbourne may need a slower feed rate in a humid Brisbane shed.

Bit style	Bearing position	Best use	Main caution
Flush-trim bit	Usually above or below the cutter	Trimming plywood to a template or matching a fitted panel	Keep the bearing clean and the template firmly attached
Round-over bit	At the lower end of the profile	Softening a sharp plywood edge	The radius must suit the panel thickness
Chamfer bit	Usually at the tip or lower end	Creating an angled edge	A large chamfer can expose several veneer layers
Beading bit	Integrated with the profile	Decorative edging on boxes and furniture	Test on scrap to avoid a heavy, uneven groove
Rabbeting bit	Bearing sets the rebate width	Cutting a step for a back, panel or trim	The bearing diameter controls the rebate depth

Start with the edge you want

The best router bit depends on the finished edge, rather than the plywood alone. A flush-trim bit is the practical choice when a panel has been cut slightly oversize and needs to match a template. Its bearing runs along the template edge while the cutter removes the excess material. This is especially useful for repeated shapes such as toy parts, lettering boards and curved cabinet panels.

A round-over bit is more suitable when the goal is comfort and appearance. A small 1.5 mm or 3 mm radius can remove the harsh corner from a shelf or plywood box without making the edge look overly styled. A chamfer bit produces a straight bevel, while a cove, ogee or beading cutter adds a more noticeable decorative line. On thin plywood, restrained profiles usually look more balanced.

For a first project, choose a bit with a bearing that is easy to see and replace. Sealed bearings are convenient because they keep much of the dust away from the race, though they still need inspection. The bearing should turn freely without rattling, and its outside diameter should match the intended guide surface.

A useful selection process includes:

• Decide whether the edge should be trimmed, softened, bevelled or decorated.
• Measure the plywood thickness with calipers rather than relying on the label.
• Check that the cutter profile will not remove too much face veneer.
• Confirm the bearing diameter and replacement availability.
• Choose a shank size that matches the router collet.

Match the cutter to plywood construction

Plywood is made from alternating veneers, so the grain direction changes from layer to layer. This gives it strength, yet it also creates several opportunities for tear-out. A sharp carbide bit helps, but cutting direction, feed speed and support are equally important. Baltic birch plywood generally machines cleanly; construction plywood may contain voids, uneven face layers or harder patches that produce a less predictable edge.

Router bits are commonly sold with 1/4-inch or 1/2-inch shanks, while Australian tools and router accessories may also be described in metric terms. Never assume that a 6.35 mm shank and a 6 mm collet are interchangeable. They are different sizes, and forcing an incorrect shank into a collet is unsafe. Check the router manual and the bit packaging before ordering. A larger shank generally offers greater rigidity, but the router must be designed to accept it.

For a flush-trim operation, the cutting length should cover the plywood thickness without extending unnecessarily far. If the cutter is much longer than the panel, vibration and leverage increase. If it is too short, the bearing may not sit properly against the template. A pattern bit with the bearing above the cutters can suit a template fixed to the top of the workpiece; a bottom-bearing version may be better when the template sits underneath.

Look closely at the bearing location before buying. The bearing is a guide, not a substitute for a secure setup. If it contacts a rough plywood edge, the bit may copy every bump. Sand or seal the template edge first, and use double-sided tape, clamps or screws outside the cutting path to prevent movement.

Work with Australian materials and conditions

Australian hardware shops such as Bunnings often stock general-purpose router bits, but specialist profiles, replacement bearings and precision pattern cutters may be easier to find through woodworking suppliers. Local makers in Sydney, Melbourne, Perth and Adelaide also commonly work with hoop pine, radiata pine, eucalyptus-faced panels and imported birch plywood. These materials vary considerably in hardness and glue content, so a test cut is more reliable than a label such as “general purpose”.

Humidity is worth considering. In Brisbane, coastal New South Wales and tropical Queensland, plywood can gain moisture and move slightly before routing. Store panels flat with spacers in the workshop for several days, particularly after delivery. In a cold Melbourne garage, allow timber to acclimatise before machining as well. A panel that is bowed or damp can press unevenly against the bearing and produce a changing edge.

Dust collection matters in an Australian shed, where doors may be open and fine dust can travel into the house. Use a vacuum connected to the router if possible, wear eye and hearing protection, and avoid loose clothing. A portable workbench can be practical for renters or apartment workshops, but it must be stable enough that the router does not pull the workpiece sideways.

When comparing specialist products, the Sloan's Woodshop catalogue can be useful for browsing woodworking accessories and related tools. Because its ordering and shipping arrangements are designed around the United States, Australian buyers should verify shank specifications, stock and delivery options before relying on a particular item.

Set up the router for a clean edge

Begin with a scrap piece made from the same plywood as the project. Set the bit so the bearing contacts the template or reference edge, then make a shallow pass. A light first cut reduces stress on the veneer and gives you a chance to inspect the profile. If a large amount of material must be removed, use a saw or jigsaw to get close first and leave only a small allowance for routing.

Feed the router in the correct direction. With a handheld router, the usual safe direction is against the rotation of the cutter, allowing the tool to push into the work rather than run away from it. Move steadily without pausing at corners. On a curved template, keep both hands on the router and slow down naturally around tight sections, but do not force the bit through the timber.

The bearing should remain in contact with the guide throughout the cut. If the guide has a dip, the cutter will follow it. If the workpiece is narrow, clamp a wider sacrificial board beside it to give the router base more support. This is particularly helpful for thin plywood strips, clock parts and small scroll saw projects.

A practical routing checklist

• Clamp the workpiece and template so neither can shift during the cut.
• Inspect the bit for chipped carbide, resin build-up or a loose bearing.
• Set the router speed according to the bit maker’s instructions.
• Make shallow passes when removing a significant amount of material.
• Support the router base fully at the beginning and end of each pass.

After routing, inspect the exit points for splintering. A small amount of painter’s tape along the cut line may support a fragile veneer, though it should not replace proper workholding. A sharp utility knife can score a delicate edge before routing, and a sanding block can remove the remaining fuzz without rounding the profile.

Buy for repeatable results

A cheap bit can be adequate for occasional softwood work, yet plywood’s glue and alternating grain can wear a low-quality cutter quickly. Look for carbide tips that are evenly ground and firmly brazed. The cutting edges should appear symmetrical, and the shank should be straight and free from corrosion. Avoid used bits with unknown damage, especially if the bearing has already been replaced with an incompatible part.

Think about the project’s scale. A small router may suit craft work, signs and boxes, while a heavier plunge router gives better control over larger panels. A trim router paired with a bearing-guided flush cutter is convenient for light edging, but it may struggle with thick hardwood-faced plywood. Match the cutter diameter, cutting length and router capacity rather than choosing solely by price.

A bearing-guided bit is also valuable for making jigs and templates. For example, a maker producing plywood quilting rulers, storage dividers or fabric-box components can cut one accurate master shape and reproduce it consistently. The related quilting project supplies are a natural companion when routed plywood forms part of a sewing-room organiser or template system, although the router bit itself should still be selected from woodworking specifications.

Checks before placing an order

• Confirm whether the router accepts a 1/4-inch, 1/2-inch or metric-style shank.
• Compare the cutter length with the actual plywood thickness.
• Check whether the bearing is top-mounted, bottom-mounted or profile-integrated.
• Ask whether replacement bearings and profile-matched parts are available.
• Factor in freight, delivery time and warranty support for Australian purchases.

After each use, brush dust from the bit and wipe away resin according to the manufacturer’s cleaning advice. Do not drop carbide cutters into a metal drawer where their edges can strike other tools. Store them in individual sleeves or a rack, and spin the bearing by hand before the next job. A router bit that remains sharp, clean and correctly matched to its guide will produce smoother plywood edges and make future projects far easier to repeat.