Shank and collet
Match nominal sizes and insert the shank to the maker's required depth without bottoming it in the spindle. Never use a mismatched or visibly damaged collet.
Power Tools / Routing / Field guide
Router Bits & Profiles
Read the shank, edge, flute and bearing geometry so each router bit makes the cut you actually intend.
4 formsCutters shown19 familiesProfiles
01 / Tool anatomy
See the assembled tool and its components
An original educational poster identifies 8 documented construction features. The numbered descriptions remain readable below the artwork on narrow screens.
- Continuous body and shank
One steel body carries the roundover profile and collet-grip shank.
- Brazed carbide cutting edge
Permanent carbide tips form the roundover; they are not removable parts.
- Detachable guide bearing
Rolls along the work edge and can be replaced with the specified size.
- Flat retaining washer
Seats with the documented bearing hardware beneath the cap screw.
- Bearing retaining screw
Secures the bearing and washer to the cutter's pilot end.
- Straight cutter comparison
The complete straight bit cuts a flat-bottomed groove or dado.
- Spiral cutter comparison
The complete upcut bit has helical flutes that move chips upward.
- Dovetail cutter comparison
The complete angled cutter forms compatible dovetail geometry.
Technical references: Freud official router-bit safe working practice and catalogs · Whiteside Machine official router-bit range · Amana Tool 49521 bearing, washer and screw specification · Whiteside essential router-bit set. The bearing-guided roundover study distinguishes a detachable bearing, flat washer and retaining screw from its continuous steel body and permanently brazed carbide cutting tips. Three complete comparison cutters retain their own straight, spiral and dovetail geometries. Original educational artwork depicts documented component groups and their relationships; it is not a service sequence or a replacement for the exact model manual.
02 / Understand the tool
What it is and what each part does
Router bits are replaceable cutting accessories, not motors or machines. A straight bit opens a groove, a spiral bit shears and moves chips along a helix, a bearing-guided roundover shapes an edge, and a dovetail bit cuts an angled wall for a compatible joint. The earlier TWG Router Bits candidate classified nineteen useful profiles; the updated study keeps those distinctions while using the approved tool-guide layout. Actual bit specifications, maximum RPM, shank and collet fit must come from the exact maker marking and instructions.
A router collet grips a clean shank while the cutter's edges remove material in the selected path. Flute geometry affects how chips and surface fibers move; an upcut spiral tends to draw chips upward, a downcut helps protect the top edge, and a compression bit uses opposing shear directions over its specified cutting length. A bearing can guide a compatible edge cut but cannot make an unsupported or excessive pass safe. The poster presents four complete bits side by side, not an exploded assembly.
Cutting edges and flutes
Edge geometry and sharpness determine the cut. A spiral's helix is not automatically upcut or downcut from appearance alone; check product labeling.
Bearing and profile
A bearing follows a suitable edge or template on bits designed for it. Confirm diameter and template relationship before cutting.
Cutting diameter
A larger diameter changes the sweep, speed limit and stock engagement. Read the exact bit's maximum speed and take shallow passes.
01 / Working relationship
How the main groups connect
02 / Edge geometry
Four profiles make four different cuts
02 / Working principle
Set, guide and control the action
These decisions make the mechanism useful at the bench.
Choose the geometry
Decide whether the cut needs a flat floor, clean top face, clean bottom face, shaped edge or matching joint.
Set the bit safely
Disconnect the router, clean the collet and shank, seat the bit correctly, tighten with the specified wrenches and set only the depth needed.
Control feed and support
Use a fence, template, bearing or table setup that supports the stock. Make a shallow test cut, then adjust for grain and chip load.
Joinery
Straight, spiral, slot, rabbeting, mortising and dovetail bits can make different groove and joint forms when guided correctly.
Edge profiles
Roundover, chamfer, cove and ogee bits shape exposed edges; larger profiles often need several passes and strong support.
Pattern work
Flush-trim and pattern bits copy a safe template edge with a bearing positioned for the actual work orientation.
03 / At the bench
Setup, technique and finish quality
Use the steps for a first pass, then inspect the work before changing the setup.
- Select a bit by cut shape, stock thickness, guide method and router capacity.
- Confirm the bit's shank, cutting diameter and speed rating against the router and collet.
- With power disconnected, clean and install the bit using the maker's insertion and tightening method.
- Secure the stock and plan a feed path with stable base or table support and dust collection.
- Take a shallow test pass in scrap, moving against cutter rotation for the normal guided cut; avoid climb cuts unless an exact controlled procedure permits them.
- Stop and let the bit fully spin down before changing depth, bearing, fence or stock position.
Spiral direction affects faces
Upcut and downcut flutes pull chips differently; compression geometry is useful only when its opposed cutting sections engage the intended faces.
A bearing is a guide
It follows a suitable reference surface but does not reduce the load of a full-width deep cut.
Profile sets the limitation
A roundover changes only an edge radius; a dovetail needs a matching entry path and cannot plunge arbitrarily into a closed slot.
What changes by model or material
Straight, upcut spiral, downcut spiral, compression, rabbeting, slot cutter, mortising and dovetail bits address different floor, edge and chip needs.
Flush trim, pattern, roundover, chamfer and cove bits depend on safe base, template or bearing support.
Roman ogee/classical, V-groove, core box, bowl/tray, raised panel and rail-and-stile profiles need compatible stock and often table-mounted setups.
Router-bit profile map
Flat-bottom grooves, dadoes and mortises; match cutting length and diameter to the setup.
Moves chips upward from a slot; support the top face if its fibers lift.
Presses chips toward the cut bottom and can preserve a clean top edge; avoid trapping chips in a deep pocket.
Opposing shear directions protect both faces only when the specified sections engage the material.
Bearing follows a template or reference edge while cutters bring stock flush.
Bearing-guided copy cutting; check whether the bearing sits above or below the edge.
Forms an outside radius; bearing size, cutter radius and depth set the transition.
Cuts a flat bevel; test depth to control the bevel's width.
Forms a concave edge; use shallow passes and back up exit grain.
Cuts a step along an edge for backs, panels or joinery.
Combines curves and flats; choose a profile proportionate to stock thickness.
Cuts angled walls for a guided dovetail or sliding joint; entry and exit geometry matter.
Makes an angled channel for lettering or decorative lines; depth changes line width.
Produces a rounded-bottom groove or channel of a specified radius.
Side cutters make a narrow slot for splines or panels; arbor and bearing must match.
Straight or spiral cutter clears a pocket in shallow passes with chip evacuation.
Large-radius cutter makes a shallow dished surface; use strong support and maker limits.
Large panel-edge profile usually needs an appropriate router table, speed and repeated passes.
Matched profile pair makes mating frame members; test the fit before production.
Choosing the tool
- Match shank and bit diameter to the router, collet and maximum speed.
- Choose carbide grade, edge geometry and flute direction for the material and visible face.
- Confirm a replacement bearing or matching rail-and-stile set from the maker when needed.
Useful accessories
- Matched collets and wrenches
- Fence or router table
- Templates and guide bushings
- Compatible bearing replacements
Consumables
- Practice offcuts
- Replacement bearings
- Appropriate bit cleaner
- Sharpening or professional service when supported
04 / Keep control
Care, troubleshooting and safety
Stop the tool and disconnect power before investigating a fault or changing a part.
Care checklist
- Brush resin from cutters with a cleaner approved for the bit and bearing.
- Inspect edges, shanks and bearings for chips, runout or rough rotation.
- Store bits separately with protected cutting edges.
- Replace damaged cutters rather than trying to run through vibration.
Common mistakes
- Using a quarter-inch shank in a half-inch collet or reducer not approved for the router.
- Bottoming the shank before tightening.
- Taking a full-depth heavy profile in one pass.
- Assuming every spiral bit pulls chips in the same direction.
Safety at the operation
- Disconnect power before bit changes and wait for full stop before touching the work.
- Observe the bit's marked maximum RPM and the router's capacity.
- Support small pieces with a jig; never hand-hold them close to a cutter.
- Use a guard, suitable feed direction and dust collection; avoid unplanned climb cutting.
When the result goes wrong
Stop; inspect sharpness, RPM, depth, feed, bearing and work support.
Check grain, flute direction, depth and use a test pass or suitable backer.
Stop; clean and inspect the matched shank and collet, then reinstall by the exact manual.
05 / Sources to keep learning
Manuals and educational resources
Use the exact tool manual for setup, limits and replacement parts. These lessons, documents and model pages teach relevant techniques or help compare real variations.
Manufacturer manuals
Freud router-bit safe working practice
Official downloads include cutter safety and handling instructions; use the PDF that matches the actual bit.
Freud bit catalogs and profiles
Official profile families, bit dimensions and application descriptions.
Learn and compare
Whiteside router-bit range
Maker source for straight, spiral, guided and specialty cutter families.
Bosch router-bit families
Official additional descriptions of bit types and accessories.
Freud router-bit application video
Manufacturer demonstration of bit forms and cut results; use written maker instructions for actual setup and limits.
06 / Manufacturer directory
Manufacturers & Brands
These maker-owned links document relevant tools and tool brands. A product brand may use another company's factory; compare the exact model before choosing parts or accessories.
Freud router bits and profile systemsWhiteside Machine router bitsAmana Tool router bits and CNC cuttersCMT Orange Tools router bitsInfinity Cutting Tools router bits and cutter setsBosch router bits
Choose parts for the exact model
Cutters, abrasives, guards, guides, dust fittings and service parts vary by tool. Check the model plate and manufacturer manual before ordering or changing a component.
Compare the Routing family →Continue through the Tools library