The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →A splined mitered joint is made by cutting matching slots across a miter and fitting a separate strip of wood into them. The spline helps align and reinforce the corner while adding long-grain glue contact. For a clean result, make accurate miters, hold the work securely in a jig, test the slot and spline fit, then glue and clamp without shifting the joint.
Choose the spline style and cutting method
Decide whether you want the spline to show on the outside corner or remain hidden. A visible spline can be a contrasting design detail. A hidden spline keeps the exterior grain pattern uninterrupted, though it may be visible inside a box when its lid is separated. Slotting can be done on individual pieces before assembly or, with a suitable jig, on an assembled box. Follow the sequence your jig supports.
The two common machine approaches are a table saw with a guided jig and a router table with a suitable slot-cutting bit and fixture. Both require secure, repeatable workholding; neither has one universal jig dimension or setup.
| Method or choice | What it involves | Key consideration |
|---|---|---|
| Table saw | A blade cuts the slot while a cradle or angled fixture guides the work. | Choose a blade and setup that produce a suitable flat-bottomed slot. Table-saw jigs are demonstrated by WOOD magazine and Woodcraft. |
| Router table | A slot-cutting bit makes the slot while a fixture supports and registers the mitered work. | Match the bit and fixture to the slot you need; clamps can help prevent movement. Woodcraft describes fixed-width and multi-cutter options. |
| Visible spline | The spline remains part of the finished outside corner. | Choose stock whose color or grain suits the intended detail. |
| Hidden spline | The spline is captured within the joint and does not interrupt the exterior grain pattern. | Depending on the box design, it may show on the inside after a lid is separated; see Fine Woodworking. |
Prepare the miters and jig
Make the mating edges fit
Cut and check the miters before slotting. They should close cleanly without gaps, and box sides should be cut to matching lengths where required. A spline will not hide a poorly fitting miter. WOOD magazine’s box tutorial emphasizes preparing the parts accurately before the slotting operation.
#1 Best Overall
- 【Aluminum Alloy Right Angle Spline Fixture】The right-angle spline jig is made of aluminum alloy, NC processing, anodized, with a solid structure, reliable, durable and wear-resistant, not easy to deform or break, and long service life.
- 【Spline Jig Suitable for】Clamping range: frame thickness 5-42mm/0.2-1.65inch, safety recommendation: frame depth 15-500mm/0.59-19.7inch. Adaptive clamping range, can be applied to more projects.
- 【Practical Design】The spline clamp can fix the frame left and right, which is more stable, providing a safer way of operation, away from danger. Ultra-low ground clearance, the workpiece is almost close to the table, high accuracy.
- 【Adjustable Corner Dovetail Jig for Table Saw Router Table】The spline clamp is more convenient to add design to your frame, can be used with table saws and planers to cut various spline grooves or dovetail keyways. Great for making picture frames, small boxes and other joinery.
- 【Package Content】You will receive 1pair aluminum alloy right angle spline jig, 1pcs hex wrench and 1pcs hex bit. Each spline jig is about 180x50x100mm/7.09x1.97x3.94inch(LxWxH), practical set for woodworking.
Build or select secure workholding
Use a purpose-built or shop-made fixture that holds the work at the required angle and registers each cut consistently. Table-saw approaches commonly use an angled cradle or fence with clamps. A router-table fixture should support the work throughout the cut; a box jig may use a mitered plywood or MDF body, a fence, and a toggle clamp. Secure the work according to the jig and machine instructions.
Test the setup in scrap
Make a trial cut in scrap from the same stock, or a close substitute. Check that the slot is where you intend, its edges are clean, and the spline fits without forcing the miter open. A flat-bottomed slot helps the spline seat cleanly. Adjust the fixture or cutter before cutting project parts.
Rank #2
- PRECISION BUILT - The Woodpeckers Spline Jig has 2 sections of aluminum Super Track, secured by UHMW glide strip lined, powder-coated steel legs. Also inlcuded are 4 molded flip stops to keep your splines aligned.
- STENGTHEN YOUR MITER JOINTS - You can make a joint rock solid and add a design element at the same time by adding spline across the miters with the Spline Jig.
- VERSATILE PROJECT CAPACITY - The Woodpeckers Spline Jig can handle narrow projects from 1/2" to 16" wide on the wider setting. When projects exceed 16", just move the tracks inward to tackle long projects up to 3 feet wide.
- TABLE SAW & ROUTER TABLE JIG - For narrow splines, this jig works great on the table saw. For wider splines or dovetail work, the jig works great with the router table too.
- MADE IN USA - Like all Woodpeckers products, the Spline Jig is precisely machined and carefully inspected in our Strongsville, Ohio, facility just south of Cleveland.
Cut the slots safely and consistently
- Set up the machine and jig: Install a cutter appropriate to the intended slot, and confirm the fixture holds the work securely and repeats the desired position.
- Register the work: Seat the mitered piece against the jig or fence and engage its clamps. On a router table, keep the piece supported and registered throughout the cut.
- Make the cut: Guide the work through the table-saw blade or router cutter using the machine maker’s operating instructions. Keep hands clear of the cutter; the router-table method described by Canadian Woodworking calls for a push stick.
- Check each slot: Confirm it is clean and consistent before cutting the remaining corners. If the slot is misplaced or the fit is wrong, correct the setup and test again rather than forcing the spline.
Fit, orient, and glue the spline
Fit the stock to the actual slot
Use spline stock that fits closely and consistently; size it to the slot you cut rather than relying on a nominal thickness. Wood, plywood, or hardboard can be used, depending on the project and the fit required. Dry-fit before applying glue so the spline seats without opening the miter.
Orient the grain for reinforcement
For added reinforcement, orient the spline grain across the joint, as advised by Canadian Woodworking and Woodcraft. The spline’s purpose is qualitative: it adds long-grain glue surface and can help register the miter. The cited how-to sources do not establish a numerical strength increase.
Recommended Free Tools
Rank #3
- Versatile Joinery Jig: Create decorative and joint-reinforcing splines for boxes, frames, cabinets, picture frames, and woodworking projects; works as a spline jig for table saw and router table applications with precise alignment control.
- Adjustable 45 Degree Sled: Durable jig base securely holds workpieces at a 45 degree angle while guiding smoothly past router bits or saw blades; ideal for spline joinery, box joint jig setups, finger joint cuts, and decorative corner details.
- Multiple Cutting Styles: Supports straight, angled, dovetail, V-groove, and custom spline patterns using router bits or table saw blades; expands woodworking versatility for furniture making, boxes, cabinetry, and trim projects.
- Precision & Stability: Aluminum miter bar with adjustable tension blocks delivers smooth no-slop movement in standard miter slots; zero-clearance inserts help reduce tear-out while adjustable fences improve positioning accuracy and repeatability.
- What’s Included: Rockler Deluxe Spline Jig For Table Saw; (1) Miter Bar with Adjustable Tension Blocks; (1) Miter Jig Base; (2) Adjustable Fences; (5) MDF Zero-Clearance Inserts; (1) Miter Stop with Easy-to-Grip Five-Star Knob; Hardware Pack.
Glue and clamp without shifting
- Dry-assemble the joint once more and confirm the corners close.
- Apply glue to the slot surfaces and spline, then seat the spline and bring the miter together.
- Clamp the corner so the miter closes evenly and the parts do not slide out of alignment. Use a clamping arrangement appropriate to the project and avoid shifting the spline during tightening.
- Leave any intended spline overhang in place and allow the glue to cure according to its label.
Trim and finish the joint
After the glue has cured, trim any overhanging spline close to the surface, then bring it flush with careful planing, sanding, or chiseling as appropriate for the workpiece. Take care not to dish the surrounding face or damage the miter. For a contrasting visible spline, keep the exposed edges clean; for a hidden spline, check the inside as well as the exterior before calling the corner finished.
Quick Recap
Best Value
- DURABLE ALLOY CONSTRUCTION: Built from sturdy alloy material, this drawer jig locator provides reliable support for repeat woodworking setup, helping maintain steady positioning during cabinet, drawer, and furniture projects.
- PRECISE FLIP LIMITERS: The integrated flip limiters make alignment easier for repeat cuts and joinery positioning, allowing this drawer clamp locator to help improve consistency when working with drawer panels and cabinet parts.
- WIDE ADJUSTABLE RANGE: Designed for flexible height adjustment, this spline clamp for table saw supports material thicknesses from 1/2 inch to 16 inches, making it suitable for a variety of woodworking applications.
- SMOOTH SLIDE OPERATION: The sliding components help reduce resistance during adjustment while protecting work surfaces from unnecessary scratches, supporting smoother setup and longer-lasting workshop use.
- MULTI-PURPOSE WORKSHOP TOOL: This table saw drawer clamp locator is suitable for furniture making, cabinet assembly, milling machine work, and general woodworking tasks, offering practical support for DIY users and professionals.
Rank #4
- This spline jig strengthen your miter joints and add a design element in the form of splines across the miters.
- Works with both table saw and router table, cut a variety of spline slots or dovetail Keyways, suitable for making picture frames small boxes and other joinery.
- Perfect for projects as narrow as 0.6 inch and up to 20 inch wide; Can clamping 5-42mm(0.2-1.7 Inch) thick frame.
- Benefit from the unique structure, there are no metal obstacles above the saw blade and router bit, can effectively avoid accidental damage; Besides, the workpiece almost close to the table top, ground clearance only 1MM.
- TOOLCOOL spline Jig is made of aluminum alloy, CNC-machined, anodized finished, robust construction, reliable and has a long service life; Come with a allen wrench and hex bit, you can operate it manually or use a hand drill.
Common problems to prevent
- The miter still has a gap: Improve the fit of the mating edges before slotting; the spline does not correct inaccurate miters.
- The spline forces the joint open: Reduce or refine the spline stock until it fits the actual slot closely without pressure that separates the miter.
- Slots vary in position: Improve how the work registers against the jig and verify the setup with scrap before cutting the project pieces.
- The spline is difficult to trim cleanly: Avoid excessive overhang and remove it carefully after the glue has cured.
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