How To: Change a Router Bit

The router is one of the most versatile tools in the shop and if you’re new to woodworking you may not know how to change a router bit.

Sometimes we are so busy producing that we forget that changing our router bits at the right time will actually help us produce more and leave you with a better product. Dull router bits can burn the wood or cause kickback, damaging the material, or worse yet, injuring you.  

The good news is that learning to change a router bit is pretty easy and you can get back to work quickly.

Step 1: Safety First

Check to make sure the router is turned off and is unplugged, or remove the battery on the router. Do not attempt to change a router bit while the router is plugged in or has a battery inserted.  

Gloves are not required but may prevent cuts. The carbide blades on the router bit are sharp and it can be pretty easy to cut yourself when inserting or removing the bit into the collet.

If you have the manual that came with your plunge router, it is a good idea to read it. Not only will it tell you how to replace the router bit, but it will give you details that are specific to your router, like where to find the spindle lock and what size router bits work with your router.

Only use bits designed for plunge routers.

Step 2: Remove the old router bit

Locate the wrench that comes with the router. Your plunge router should have come with an open-end wrench. They’re usually packaged separately and not connected to the router as you see on other power tools.

If you’ve lost yours, you can also use an open-end or adjustable wrench. Adjustable wrenches can get the job done as well, but a bit harder to work with if you are trying to change a blade without removing the plunge base from the motor housing first.

The easiest way to access the spindle to loosen the collet nut is by removing the plunge base from the motor housing. Do this by setting the router on the motor with the router bit pointing up.

Locate the motor clamp on the side and flip it open. Pull the plunge base up and away from the motor housing.  If you decide to keep the base on the motor housing, unlock the plunge lock lever or the motor housing clamp so that the base slides out enough to get a wrench on the nut and collet.

Next, we are going to loosen the collet that holds the router bit.

Locate the spindle lock lever or button. Pressing this button will lock the spindle in place so that you can loosen the nut that tightens the collet around the router bit using your wrench. Some routers may not have a spindle lock and require one open-end wrench to hold the spindle while loosening the nut with a second.

While keeping the spindle locked, use the wrench to loosen the nut counterclockwise.

Loosen the nut just enough so that the router bit slides out easily. 

Do I Need to Change the Collet?

You do not need to remove the nut and collet from the spindle unless the replacement router bit has a different shaft diameter and requires a matching collet.

Most bits are either 1/4″ or 1/2″ shafts and they need a matching collet so it’s helpful to have a couple collets of each size for flexibility.

To change the collet, unscrew the nut and collet and remove it from the spindle. Push out the collet from the nut and press in the new collet until it snaps in place.  Screw the nut and collet onto the spindle, but keep it loose enough to insert the replacement router bit.

step 3: install the new router bit

Before installing the router bit, be sure to inspect and remove any debris from the collet with high-pressure air.  The collet works by compressing around the shaft of the router bit and debris can get in the way when tightening the nut.

With the nut and collet screwed on to the spindle, insert the router bit all the way into the collet until it stops.  If the router bit cannot be inserted, loosen the nut until it slides into place.  

Slide the bit back out of the collet about ⅛” to ¼” and tighten the nut by hand until it stays in position. The router bit must be inserted in the collet at the correct depth according to the manufacturer’s instructions to prevent the bit from flying out or breaking while in operation.

With the spindle locked, use the wrench to tighten the nut clockwise and firmly in place.

Slide the plunge base back onto the motor housing and clamp in place.

step 4: check the router bit and get to work

Pull on the bit to make sure it is secure in the collet and does not slide out.

Make sure the base is fully extended and set at zero depth of cut. Plug in the router and verify that the router and router bit spin normally. Look out for any wobbly bits.

Adjust the router base to the desired depth of cut. Using a scrap piece of wood, do a test run on the edge to make sure the bit cuts smoothly, as expected.

If the router stops while performing the test, check to make sure the bit is not loose in the collet.  Unplug the router and tighten the nut more and test again.

Adjust as necessary until the router is moving smoothly and consistently through the material. Now you know the basics of how to change a router bit. Go make something great!