What is the difference between countersunk, pan, flange and dome head screws?
Head shape decides whether a screw pulls itself into the material or stops on top of it — and picking the wrong one either splits the workpiece or leaves the head proud.
- Difficulty
- beginner
- Time
- 10 min
- Read
- 3 min
Short answer
Countersunk heads have a cone underneath and pull themselves flush into a matching recess. Pan, flange and dome heads have a flat underside and stop on the surface. Use countersunk where the head must disappear and you can cut a recess; use a flat-bottomed head on thin, soft or pre-drilled material where you cannot.
The head is the only part of a screw that touches the thing you are fixing, so it decides how the load gets from the fixing into the material. The diagram shows each head in section with the material beneath it, which makes the difference obvious in a way a photograph does not.
Step by step
- Countersunk: use where the head must finish flush.The underside is an 80 to 90 degree cone. It needs a matching conical recess — cut with a countersink bit in hardwood and metal, or self-formed by the head in softwood if you accept some crushing. Driven hard into a flat surface it acts as a wedge and splits timber.
- Raised countersunk: use where the fixing is on show.The same cone below, a domed top above, so it deliberately stands proud. This is the head that belongs in a screw cup on door furniture, hinges and cabinet handles.
- Pan head: use on thin material and pre-drilled holes.A shallow cylinder with a flat underside that bears on the surface. Nothing wedges, nothing widens the hole, and it is the right choice on metal brackets, plastics and anything with a hole already in it.
- Flange or washer head: use where the material is soft or the hole is slotted.A pan head with an integral skirt, giving a much bigger bearing area without a separate washer. It stops the head pulling through soft board and spans a slot or an oversize hole.
- Dome or button head: use for appearance.A low rounded head with a smaller bearing area than a flange, chosen because it looks tidy and has nothing sharp on it. Not a load-carrying choice.
- Bugle head: use on plasterboard.A countersunk head whose cone is curved rather than straight, so it compresses the paper face rather than cutting through it. This is why plasterboard screws look different, and why they should not be used as general screws.
- Match the head to what is beneath, not to what you have in the tin.The commonest error is a countersunk head driven into a flat sheet or a plastic fitting, where the cone acts as a splitting wedge on something that has no strength to resist it.
Tips
- A screw cup is not decoration — it also gives a raised countersunk head a wider bearing surface and stops the head crushing into the finish every time the item is unscrewed.
- On soft timber a countersunk head will sink itself, which looks fine until it dishes the surface and starts holding water outdoors. Cut the recess.
- If you need a big bearing area and only have countersunk screws, a countersunk-and-cup or a separate flat washer under a pan head is the field fix.
Common mistakes
- Using a countersunk head on a metal or plastic bracket with a plain round hole — The cone bears on the edge of the hole only, so it distorts the bracket and never seats. Those holes want a pan or flange head.
- Using bugle-head plasterboard screws for general fixing — They are brittle, thinly coated and have poor shear strength. They snap where a proper screw would flex.