What Is a Plunge Router Used For?

How a plunge router works

A plunge router rides on a pair of spring-loaded posts. With the motor running and the base resting flat on the work, you press the motor down, the bit enters the wood, and you lock it at the depth you want. When you finish the cut, you release the lock and the springs lift the bit clear.

A fixed base router works differently. You set the bit depth first, then the bit is already exposed when you set the tool on the wood. That is fine at an edge, where the bit can approach from the side. It is risky and hard to control in the middle of a board.

Plunge bases also come with a depth stop, often a turret or a stepped rod. This lets you cut deeper in several passes and return to the same depth each time.

What a plunge router is good for

The common thread is any cut that begins or ends inside the board instead of at an edge. Here are the jobs people reach for a plunge base to do:

• Mortises for mortise and tenon joints, where a rectangular pocket must start in the middle of a rail or leg.
• Stopped grooves and flutes, which begin and end before the board's edge.
• Dados and shelf grooves cut across a panel, guided by a straightedge.
• Inlays and recesses, such as a pocket for a hinge, a decorative strip or a name plate.
• Sign carving and lettering, where each letter starts at its own point.
• Template work, where a guide bushing follows a pattern and the bit plunges into the shape.

Plunge or fixed base: which tasks suit each

Many routers today ship as combo kits with both bases, so the choice is often about which base to put on for a given job. Every product on our best plunge router page lists a fixed and plunge base type, so you do not have to pick one and give up the other.

Use this table as a quick guide.

Features that matter for plunge work

Because plunge cuts remove a lot of material in one spot, a few specs matter more than they do for edge work. Our best router comparison covers routers in general, and the points below apply when plunging in particular.

Motor power affects how well the router holds its speed in a deep cut. Among the models on our plunge page that list watts, the Triton TRA001 lists 2400 W, while the Bosch 1617EVSPK lists 1678 W and the VEVOR palm kit lists 710 W. Hardwood and deep mortises favor the higher end. Palm-size kits suit lighter trim and small recesses.

Depth control is the other big one. The DEWALT DW618PKB has a micro-fine ring that adjusts in 1/64-inch increments. The Bosch GOF13-25 has an integrated depth stop with eight-stop increments for multiple passes. The WORKPRO kit uses a rack and pinion depth knob. Small, repeatable steps make inlay and mortise work easier to get right.

Speed range and soft start also help. Variable speed lets you slow down for larger bits. Soft start reduces the jolt when the motor spins up, which keeps the router steadier as you lower the bit.

How to make a basic plunge cut

The steps below cover a simple stopped groove or mortise. Always check your router's manual for its specific locking and bit-change steps.

• Unplug the router, or remove the battery on a cordless model, before you install or change a bit.
• Insert the bit shank fully into the collet, back it out a little, then tighten it. Make sure the collet size matches the bit shank.
• Clamp the workpiece firmly. Mark the start and end of the cut, and clamp a straightedge or fence if you need one.
• Set the depth stop to your final depth. For deeper cuts, plan several passes and set the turret or stop step by step.
• Set the speed. Use a lower setting for large bits and a higher one for small bits.
• Rest the base flat on the work with the bit above the surface. Start the motor and let it reach full speed.
• Press the motor down smoothly to the stop and lock it if your model has a lock.
• Move the router steadily along the line, then stop at the end mark, release the lock and let the bit rise before lifting the tool.
• Switch off and wait for the bit to stop spinning before you set the router down.

Safety notes

Routers are loud and throw chips at speed, so wear eye protection and hearing protection every time. A dust mask helps too, especially with MDF and hardwoods.

Keep both hands on the handles and keep the cord clear of the bit's path. Never reach under the base while the bit is turning. Let the router come to a full stop before setting it down, because the bit can still be spinning after you switch off.

Secure the workpiece with clamps instead of holding it by hand. Take shallow passes in hard woods rather than forcing one deep cut, which can stall the motor and cause the router to grab.

Do you need one?

You need a plunge router if you plan to cut mortises, stopped grooves, inlays or pockets away from an edge. If your work is mostly edge profiles and flush trimming, a fixed base will cover it.

For most people who want room to grow, a plunge and fixed combo is a sensible middle path, since one motor serves both bases. Weight matters for hand-held work. On our plunge page the listed weights run from 7.5 lb to 22.18 lb, so check that number before you commit, especially if you will route overhead or for long stretches.

Frequently asked questions

Can a plunge router do edge work too?

Yes. You can lock the plunge base at a fixed depth and use it for edge profiles. Many people still prefer a fixed base for edge work because it is lighter and lower to the work.

Is a plunge router harder to use than a fixed base?

It takes a little practice to lower the bit smoothly and keep the base flat. Starting with scrap wood and a clamped straightedge makes the first few cuts easier.

What size collet do I need?

The collet must match the shank of the bit you want to use. Some models on our list state a 1/4 in collet, and the WORKPRO kit lists 1/4 inch and 3/8 inch collet cones. If a listing leaves the collet size out, ask the maker.

Can a cordless plunge router handle the same jobs?

For many light to medium cuts, yes. The DEWALT DCW620B on our page lists 1678 W and a tool-free depth system, but the battery is sold separately. Check run time for long jobs.