How to Use a Biscuit Joiner

What Is a Plate Jointer?

Plate jointers (or joiners) are used to quickly and accurately make simple plunge cuts into most types of wood and wood products to join two or more boards or pieces using small, thin football-shaped pieces of wood called biscuits. Glue and a biscuit are placed inside each slot and help to line up adjoining surfaces, creating a strong seam.

Aliphatic resin glue, carpenters glue, hide glue, white glue, and yellow glue are all examples of water-based glues. The biscuits swell inside the joint when water-based glues are used, making a durable bond. The material surrounding the biscuit will be more likely to break than will the biscuit.

Spline joinery, accomplished by cutting slots and splines (thin strips of wood) with a router or table saw, used to be limited to creating edge-to-edge joints. With the use of a plate jointer, butt, miter, and T-joints can now easily be joined using biscuits, and the finished seam will be as strong as doweled joints, mortise and tenon, tongue and groove, and standard spline.

How to Make Adjustments to Your Plate Jointer

See your owner’s manual for diagrams that indicate part names.


Biscuits come in three standard sizes – #0, #10, and #20. To set the depth adjustment knob, follow these three steps:

  1. Unplug the plate jointer.
  2. Pull the spring-loaded jam nut and knurled adjustment knob out from the unit. This releases the pressure from the depth adjustment knob.
  3. Tabs for 0, 10, and 20 are on the rear base assembly. Rotate the depth adjustment knob to match the tab for whichever biscuit size you want to use.

If, after making a test cut on a scrap of wood, you find that the slot is too deep or too shallow for the correct biscuit size, you can make a fine adjustment. Be sure to unplug your plate jointer before beginning. The knurled adjustment knob is used only as a lock nut. Loosen it by twisting it away from the jam nut. Adjust the jam nut, forward for a more shallow cut, and backwards for a deeper cut. Check your adjustment on another scrap of wood.

Fence Height:

The fence positions the blade in relation to the top of the work piece.

  1. Unplug the plate jointer.
  2. Loosen both height adjustment knobs (one on either side of the fence) about one turn.
  3. Align the indicator point with the desired setting on the height setting scale.
  4. Tighten both height adjustment knobs.

Fence Angle:

Angles can be set from 0 degrees to 135 degrees in 45-degree increments. Each 45-degree positive stop angle is indicated by an audible click as you rotate the adjustable fence.

  1. Unplug the plate jointer.
  2. Loosen both height adjustment knobs (one on either side of the fence) about one turn.
  3. Rotate the fence to the desired angle.
  4. Tighten both height adjustment knobs.

How to Operate Your Plate Jointer

Depth of cut and location of cut are the basic adjustments that you have to make for all biscuit joinery applications.

Basic Joints

  1. Unplug the plate jointer.
  2. Lay the work pieces adjacent to each other in proper assembly order.
  3. Draw a line across each work piece to indicate the center of each biscuit joint.
  4. Set the fence angle at 90 degrees.
  5. Select the depth of cut that matches the biscuit size you want to use.
  6. Clamp the work piece.
  7. Plug in the plate joiner and grip the unit firmly with both hands, using both the front and the rear handles.
  8. Aligning the fence indicator marks with the center line marks on the work piece, place the fence against the board.
  9. Press the switch trigger and push the plate jointer forward.
  10. When the front base assembly hits the board and stops moving forward, pull back to release the pressure on the spring. The blade will retract from the biscuit slot.
  11. Make sure the joints line up properly and all pieces fit correctly by placing biscuits in the joints and dry assembling the work pieces after all the biscuit slots have been cut.
  12. Disassemble pieces and reassemble after applying glue in each slot and along the surface of the joint.
  13. Reassemble and clamp work pieces together until the glue sets.

Your owner’s manual has precise angle degrees for different types of joints as well as diagrams to assist with the operation of your plate jointer.

Important Safety Tips

Before operating your plate jointer, take a few minutes to read the owner’s manual. Familiarize yourself with hazards and recommended operational procedures.

If the handle of the unit is cracked or broken, don’t use it. Electrical shock could occur if you touched anything metal that is grounded.

Do not use if you or the plate jointer are wet or while standing on a damp or wet surface.

Wear safety glasses.

Keep children away from all power tools.

Protect the cord. Keep it away from heat, and don’t yank on it to disconnect it from an outlet.

If you must use an extension cord, verify that it is heavy enough to carry the current your plate jointer will use. This information is contained within the specifications section of your owner’s manual. A smaller gauge number indicates a heavier cord. If you’re using your plate jointer outside, make sure your extension cord is approved for outdoor use. They will be marked with a suffix of W-A. Replace extension cords at any sign of damage; inspect frequently.

Use clamps to hold pieces of work together.

Ensure that you have stable, secure footing.

When not in use, disconnect from power source.

Ensure the switch is turned off before you turn the tool on. Don’t carry it with your finger on the switch trigger.

Keeping the blades sharp and clean will prevent kickback and stalling. If the blade or the jointer stalls, immediately release the switch to avoid injury caused by kickback. If you continue to attempt to operate the unit with the blade stalled, the plate jointer will be thrust in the direction opposite to the blade rotation. Serious injury can result.

After you switch the unit off, the blade will continue to coast for a while, so keep your hands away. Do not reach under your work while the blade is turning, and do not lay the unit down until the blade has stopped.

As with all motors, operate away from fumes, gases, and flammable liquids.

Do not use the unit if the cord shows any sign of damage. Maintain a safe distance at all times between the cord and the machine when you’re operating it.

Do not use strong solvents, brake fluids, gasoline, or petroleum-based products to clean your plate jointer. Using a clean cloth when cleaning will keep the handles dry and avoid a buildup of grease and oil.

Use only the four-inch diameter blades specified to be used with your unit.

Be careful, be safe, and enjoy your new power tool as you create beautiful additions for your home.

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