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Draft – being checked by a qualified joiner

Curves: cut, bend, laminate and edge them

Tap your job. See which method suits it, the tools, the steps and the usual mistakes. For how tight a sheet will bend, always check the maker's data sheet.

Easy to hard5 methodsCurve pickerRouter safety

Router feedPick your curve jobThe five methodsKerf spacingCommon mistakes

Draft – being checked by a qualified joiner. This page is new. A qualified joiner is checking every part of it, so some details may change. It's general know-how, not a rule book. Don't rely on this page alone: check the maker's sheet and ask your supervisor. Spotted a mistake? Tell us.

The big rule

Feed the router against the spin of the bit.

Hand-held router, seen from the top: go anti-clockwise around the outside of a job, and clockwise around the inside. Router table: feed right to left. The other way is a climb cut. The bit can grab the job, or the router, and throw it.

See which way to go

// 01 Router feed

Which way does the router go?

Watch the router go around the job. Then tap "Show the wrong way" to see what a climb cut does.

Right way: against the spin of the bit. The bit pushes back against you, so you stay in control. Wrong way: with the spin of the bit (a climb cut). The bit grabs and pulls. The job or the router can be thrown.

the job outside:anti-clockwiseinside:clockwise WRONG WAY:climb cut The bit grabs and throws it. Feed against the spin.
Hand-held router, seen from the top. Not to scale.
starting pin bit + bearing Feed right to left Wrong way: climb cut
Router table, seen from the top. Not to scale.

// 02 Check before you cut

Check before you cut, bend or glue.

General safety notes, not a full list. Follow your site rules, the product's SDS and your supervisor.

// 03 Pick your curve job

Pick your curve job.

Two quick taps. See which method is often used for your job.

Try it: tap your job

1What's curved?

2How many parts?

  • Try: Cutting curves and template routing. Cut it, don't bend it. Make a smooth template, then rout to it.

    Uses a router: feed against the spin. No climb cuts. No small parts.

    Show me this method

  • Try: Cutting curves and template routing. One good template makes many matching parts. Or use a CNC.

    Uses a router: feed against the spin. No climb cuts. No small parts.

    Show me this method

2How is it used?

  • Try: Bendy ply and flexible MDF. Bendy sheet over formers. Kerf bending is another way.

    Show me this method

  • Try: Bent lamination over a form. Thin layers glued over a form hold the shape and are strong.

    Show me this method

  • Try: Kerf bending. Saw cuts across the back let it bend. Test the spacing on scrap.

    Show me this method

2What goes on the curve?

  • Try: Laminating and edging curves. Glue it onto a curved panel. Tight edges like a bullnose are postformed by a fabricator.

    Uses a router: feed against the spin. No climb cuts. No small parts.

    Show me this method

  • Try: Laminating and edging curves. Check the edging's bend radius on its data sheet.

    Uses a router: feed against the spin. No climb cuts. No small parts.

    Show me this method

Tight curve? Check the maker's data sheet for your exact sheet, and test on scrap first. See the data sheets

These are common choices, not the only ones. Many shops have their own way. Ask what yours uses.

// 04 The five methods

Five ways to make a curve.

Tap a method. See when it's used, the tools, the steps and the usual mistakes.

Not sure which method? Pick your job
feedanti-clockwise template (MDF) under the jobthe job bearing runs onthe template
Top view. The template (MDF) is under the job. Not to scale.

Method 1 of 5

Cutting curves and template routing

Easy to mediumRouter

The curve is in the outline of a flat part: rounded benchtop ends, arched doors, shaped shelves, and lots of the same part. It's also how you make formers and forms for the other methods.

Uses a router: feed against the spin. No climb cuts. No small parts.

Tools

  • Jigsaw or bandsaw for the rough cut.
  • MDF for the template, and a sanding block.
  • Router with a flush trim bit, a pattern bit or a guide bush.
  • Double-sided tape, screws in the waste, or clamps.

Steps

  1. Draw the curve full size. A thin, bendy batten through three points gives a smooth arc.
  2. Make the template from MDF. Cut just outside the line, then sand to the line until it's fair (smooth). Every bump copies onto every part.
  3. Fix the template to the job, with tape, screws in the waste, or clamps clear of the router.
  4. Rough-cut the job just outside the line, so the router only takes a light trim.
  5. Pick the bit: template underneath, flush trim bit. Template on top, pattern bit. Guide bush: allow for the offset.
  6. Set the depth so the bearing runs on the template, not on the rough edge.
  7. Feed against the spin of the bit, with the bearing pressed lightly on the template.

Mistakes and fixes

  • Bumps on the curve: the template wasn't fair. Fix the template, not the part.
  • Burn marks: blunt bit, stuck bearing, or feed too slow. Bosch: "Feeding too slow" leaves friction burns. Bosch (PDF) (opens in a new tab)
  • Bit grabs, job jumps: wrong feed direction, too big a bite, or the part is too small. Stop. Use a bigger blank or a jig.
  • Part comes out the wrong size: guide bush offset not allowed for, or a bearing that's a different size from the cutter.

Maker data and sources

Watch

We don't give bend radii or spacings of our own. Every product is different, so always check the maker's data sheet for the exact product.

Kerfs on the inside of the curve former test the spacing on scrap first
Side view. The kerfs go on the inside of the curve. Not to scale.

Method 2 of 5

Kerf bending

MediumSaw

Many saw cuts across the back of a board let it bend. Used when the board is thicker than bendy sheet, and the back won't be seen or will be covered.

Tools

  • A saw that cuts to a set depth (table saw, track saw or CNC).
  • A way to space the cuts evenly, like an indexing jig.
  • Scrap of the same board, for test pieces.
  • Formers, glue and filler.

Steps

  1. Find the spacing with the lift test (see below). There's no magic number.
  2. Cut a test piece and bend it over the former.
  3. Adjust: flat spots mean kerfs too far apart. Cracks mean too deep, or too tight.
  4. Cut the real part, with the kerfs on the inside of the curve.
  5. Bend it over formers. Glue or fix it. Fill the kerfs if it needs to be stiff.
  6. Cover the kerfed face, or put it where it won't be seen.

Mistakes and fixes

  • Flat spots on the face: kerfs too far apart. Space them closer and test again.
  • Face cracks along a kerf: too deep, or the curve is too tight for that board.
  • Uneven curve: uneven spacing or depth. Use a jig or a CNC.
  • Many repeat cuts on the saw: keep the guard on and use push devices. Never reach over the blade.

Maker data and sources

Watch

We don't give bend radii or spacings of our own. Every product is different, so always check the maker's data sheet for the exact product.

Top view: sheet bent over formers formers (ribs) fixed toeach former How tight? Read the data sheet for the exact sheet.
Top view. The sheet is fixed to every former. Not to scale.

Method 3 of 5

Bendy ply and flexible MDF

Easy to mediumFormers

Curved cabinet fronts, end panels, kickboards, column wraps and desk fronts. Quicker than kerfing, with a smooth face. The sheet isn't structural: it needs a frame or formers.

Tools

  • Formers or ribs (cut with template routing).
  • The glue the sheet maker recommends.
  • Screws or pins, clamps or straps.

Steps

  1. Pick the bend direction: long grain or short grain. Order the right one. You can't turn it round later.
  2. Check the radius against the maker's data sheet. Tighter? Use another method, or test first.
  3. Make the formers. Space them as the maker says.
  4. Dry-fit first. Bord says for bending MDF: "The grooved face always faces inward against the supporting framework". Bord: Bending MDF (opens in a new tab)
  5. Glue and fix it to every former. Leave it for the glue maker's full time.
  6. Fill and finish as the maker's sheet says.

Mistakes and fixes

  • Wrong grain direction ordered: check long or short grain before you cut.
  • Flat spots between ribs: ribs too far apart. Bord: "Tighter curves require closer rib spacing to prevent flat spots". Bord (opens in a new tab)
  • Grooves show through laminate or paint: thin surface on a tight curve. Check the data sheet.
  • A loose bendy ply door bows: Bord warns about non-fastened cabinet doors. One seller says: "This plywood is not suitable for use in the manufacture of doors". PPS data sheet (PDF) (opens in a new tab)

How tight will it bend? Read the sheet you bought.

These are word-for-word quotes from Australian sellers' pages and data sheets (checked October 2026). Look how different they are.

Product (seller)What the seller saysSource
Bord Bendy Ply“5mm thickness: 220mm minimum radius / 8mm thickness: 400mm minimum radius”Bord: Bendy Ply (opens in a new tab)
Ply Online Bendy Plywood“Bending Radius (measured on the dry sheets): 5mm plywood - 150mm, 8mm plywood - 200mm”Ply Online (opens in a new tab)
Plywood & Panel Supplies Bendy Plywood“bending radius at minimum is 300mm for 5mm sheets and 300mm bending radius for 8mm sheets”PPS data sheet (PDF) (opens in a new tab)
Austral Bendy (hoop pine)“The recommended minimum bending radius for Austral Bendy is 200mm.”Austral guide (PDF) (opens in a new tab)
Laminex Craftform (flexible MDF)“a radius of down to 200mm being achievable”Laminex brochure (PDF) (opens in a new tab)
Bord Bending MDF MR“approximately 200mm minimum radius”Bord: Bending MDF (opens in a new tab)
DMK Craftform Flexible MDF“The minimum bend radius depends on the thickness and cut direction”DMK Forest Products (opens in a new tab)

Three 5mm bendy plys, three different figures. Same name, different product. So check the maker's data sheet for the exact sheet you bought, and test on scrap.

Maker data and sources

Watch

We don't give bend radii or spacings of our own. Every product is different, so always check the maker's data sheet for the exact product.

form (mould) Thin layers, glue on every face,clamped over a form
Side view. Thin layers glued and clamped over a form. Not to scale.

Method 4 of 5

Bent lamination over a form

HardFormGlue

Strong, clean curved parts with no grooves: rails, aprons, thick curved doors, chair parts. Popular Woodworking says bent laminations "are actually stronger than if the piece were cut from a single block of wood". Popular Woodworking (opens in a new tab)

Tools

  • A form, made from layers of MDF.
  • Thin strips (plies) of timber or veneer.
  • A rigid glue, lots of clamps, or a vacuum bag.
  • Packing tape or waxed paper, so glue won't stick to the form.

Steps

  1. Make the form from stacked MDF, cut and faired with template routing.
  2. Line the form, and tape or wax it so the glue won't stick.
  3. Cut the plies. Test-bend one dry ply on the form before any glue goes on.
  4. Dry-run the clamp-up. Have every clamp ready.
  5. Glue every face evenly, stack the plies, and clamp from the middle out.
  6. Leave it for the glue maker's full time. Then take it off. Expect a little springback.
  7. Clean up the edges with a router or saw.

Mistakes and fixes

  • Springs open too much: use a rigid glue. Popular Woodworking: "Yellow glue sets soft and fast. It is also prone to glue creep". Popular Woodworking (opens in a new tab)
  • Gaps in the glue lines: form not fair, or too few clamps.
  • Raised glue lines months later: glue creep. Use a rigid glue for stressed bends. Woodweb: glue creep (opens in a new tab)
  • Plies crack when bent: too thick for the curve. Cut them thinner and test one dry.

Maker data and sources

Watch

We don't give bend radii or spacings of our own. Every product is different, so always check the maker's data sheet for the exact product.

curved panel (top view) Edging (or laminate) worked around the curveCheck its bend radius on the data sheet
Top view. Edging worked around a curved panel. Not to scale.

Method 5 of 5

Laminating and edging curves

MediumLaminateEdging

Putting a laminate face or an edge on a curved part: curved fronts, rounded benchtop ends, desks and shaped shelves.

Uses a router: feed against the spin. No climb cuts. No small parts.

What Laminex says

Steps (laminate on a curve)

  1. Build a smooth, fair curved panel first (kerf, bendy sheet or lamination). Lumps show through.
  2. Check the laminate's radius and sheet direction on its data sheet.
  3. Cut the laminate oversize. Contact adhesive on both faces, as the glue maker says.
  4. Lay it from one end and roll it around the curve. Don't trap air.
  5. Trim with a flush trim bit: clean bearing, right feed direction.

Edging on a curve

  • Check the edging's bend radius on its data sheet.
  • ABS edging can whiten on a tight bend. Laminex says the colour "can be restored by applying heat such as with a hot air blower". Keep heat well away from contact glue fumes. Laminex/Formica ABS sheet (PDF) (opens in a new tab)
  • Most straight-line edgebanders can't follow a curve. Curves need a contour edgebander, a hand-held edger, or edging applied by hand.

Mistakes and fixes

  • Laminate cracks: curve tighter than the data sheet. Use a gentler curve, or get it postformed.
  • Ends spring up: Laminex says "mechanical fastening may be required, to prevent the laminate from springing back". Laminex (opens in a new tab)
  • Edging lifts on the curve: the curve is too tight for that edging, or not enough pressure all the way around.

Maker data and sources

Watch

We don't give bend radii or spacings of our own. Every product is different, so always check the maker's data sheet for the exact product.

// 05 Kerf spacing

Find your kerf spacing: the lift test.

No magic number. Every board, blade and curve is different, so you test it.

bench clamp this gap = your kerfspacing (roughly) kerf just closes kerf to mark = the radius you want The lift test (on scrap of the same board)one kerf
Side view, on scrap of the same board. Not to scale.
  1. Cut one kerf in a long scrap of the same board, at the depth you'll use.
  2. From the kerf, measure along the board the radius you want. Mark it.
  3. Clamp the board flat to the bench on one side of the kerf.
  4. Lift the free end until the kerf just closes.
  5. At your mark, measure the gap under the board. That's roughly your kerf spacing.

Then test-bend a sample. What does it show?

Smooth curvegood spacing
Use this spacing for the real part.
Flat spotskerfs too far apart
Fix: space the kerfs closer, then test again.
Face crackstoo deep or too tight
Fix: cut a bit shallower, or make the curve gentler.

Every board is different. Test on scrap of the same board. The lift test is from a Fine Homebuilding forum (opens in a new tab) post: "Takes some fine tuning, but that gets you in the ballpark." Fine Woodworking: "Probably best to test the output of the calculator anyway". Fine Woodworking (opens in a new tab)

// 06 Words

Words you'll hear.

Tap a word to see what it means.

Radius

The distance from the centre of a circle to its edge. A small (tight) radius is a sharp curve. A big radius is a gentle curve. Radius is half the diameter, so don't mix them up.

Convex and concave

Convex bulges out towards you, like the outside of a ball. Concave curves in, like the inside of a bowl. Some data sheets give a different limit for each.

Former or rib

The curved pieces (often MDF or particleboard) that a bent sheet is glued and fixed to, to hold its shape.

Form (mould)

A shape you bend thin strips over, then glue and clamp until the glue sets.

Template (pattern)

A smooth, accurate copy of the shape, often MDF. The router bearing runs along it.

Flush trim bit

A router bit with a bearing the same size as the cutter, at the tip. It trims the job flush with the template.

Pattern bit

Like a flush trim bit, but the bearing is on top, near the shank. Handy when the template is on top of the job.

Guide bush

A ring on the router base that runs along the template. The cut is offset from the template, so make the template bigger or smaller to suit.

Climb cut

Feeding the router with the spin of the bit. Risky. See the safety box.

Kerf

The slot a saw blade cuts. Kerf bending means many saw cuts across the back of a board so it can bend.

Bendy ply (flexi ply)

Thin plywood made to bend one way. Long grain bends along the sheet. Short grain (cross band) bends across it. Shops use different names, so check the label.

Bendy MDF (flexible MDF)

MDF with grooves cut into the back so it bends. Laminex's version is called Craftform.

Springback

When a bent part opens up a bit after you take it off the form.

Creep

When a glue line slowly moves under stress, so a bent part can lose its shape.

Telegraphing

When grooves, kerfs or lumps underneath show through the finish.

HPL

High-pressure laminate, like Laminex or Formica sheet laminate.

Cold-forming

Gluing laminate onto a panel that's already curved, with no heat.

Postforming

Heating laminate in a machine so it bends around a tight edge, like a rounded benchtop front (a "bullnose").

Fair curve

A smooth curve with no bumps, flat spots or kinks.

Kickboard (plinth)

The board at the bottom of base cabinets, between the cabinet and the floor.

Chippy

Aussie slang for a carpenter.

"She'll be right"

Aussie for "it'll be fine". A bad thing to think about a tight curve. Test it first.

// 07 Common mistakes

Common mistakes, and the fix.

Tap a mistake. Then tap "Show the fix".

Problem: bumps on the curveThe template wasn't fair Fix: fair the template, not the partEvery bump copies onto every part

Bumps on the curve

What you see
Lumps or flat spots on a routed curve.
Why
The template wasn't fair. The bearing follows every bump.
Fix
Fix the template, not the part. Sand it fair, then rout again.
Next time
Run your hand along the template before you use it. Check it by eye from the end too.
Problem: flat spotsFormers too far apart Fix: formers closer togetherAs the maker's sheet says

Flat spots on a bent sheet

What you see
The curve looks like it has flat sides.
Why
The formers (ribs) are too far apart for that curve.
Fix
Add formers, closer together.
Next time
Space the formers as the maker's data sheet says.
Problem: springs open off the formSoft glue, or thick layers Fix: rigid glue, thinner layersThen test. Expect a little springback.

Lamination springs open

What you see
The part opens up a lot after it comes off the form.
Why
A soft glue (like yellow PVA), or plies that are too thick.
Fix
Use a rigid glue, like a two-part glue or epoxy, and thinner plies. Then test.
Next time
Do a test piece first. Read the glue maker's data sheet for times.
Problem: laminate cracksCurve tighter than the data sheet Fix: gentler curve, or postformCheck the laminate's data sheet

Laminate cracks on a curve

What you see
Cracks or white lines in the laminate on the bend.
Why
The curve is tighter than that laminate allows, or the sheet runs the wrong way.
Fix
Use a gentler curve, or get it postformed by a fabricator.
Next time
Check the laminate's data sheet for its radius and sheet direction before you start.

// 08 Quick check

Quick check.

Six quick questions. Tap an answer.

Question 1 of 6 · Score 0

1/6 Hand-held router, outside edge of a job, seen from the top. Which way do you go?

Answer: Anti-clockwise. Anti-clockwise around the outside, against the spin of the bit. Clockwise around the inside.

2/6 You need a small curved part. What's safer?

Answer: Rout a bigger blank, then cut the part out. Don't rout small parts. Rout a big blank, or use a jig.

3/6 Two bendy plys are both 5mm thick. Will they bend to the same radius?

Answer: Not always. Check each maker's data sheet. Australian sellers list different figures for sheets that look the same.

4/6 Kerfs are showing as flat spots on the face. What do you change?

Answer: Kerfs closer together. Closer kerfs give a smoother curve. Test on scrap of the same board.

5/6 Which glue holds a bent lamination's shape best?

Answer: A rigid glue, like a two-part glue or epoxy. PVA sets soft and can creep. A rigid glue holds the shape.

6/6 A benchtop needs a tight, rounded front edge in laminate. What's that called?

Answer: Postforming. Postforming heats the laminate in a machine. It's usually a fabricator's job. Cold-forming is for gentle curves.

You got 0 of 6.

// 09 Sources

Where this comes from.

Maker sheets, seller pages and safety pages we used. Always check the current version.

Show all 27 sources

Router safety

Dust and glue safety

Bendy sheet data

Laminate and edging

Technique

Stuck on a curve? Ask Barry. Barry Biscuit, the AI joiner mate, answers in simple English. AI · beta

Try:Which curve method?Which way to feed the router?How tight will bendy ply bend?How far apart are kerf cuts?Laminate cracking on a curve

AI beta: Barry is an AI and can be wrong. Always check with your supervisor and the maker's instructions.

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