Two doors, same machine builder, same week. One got flat heads all down the row. The other got raised heads with illuminated centers, plus one mushroom. Both panels were, by any standard, correct. The difference between them was not right versus wrong. It was what each door was going to be touched by, and how often, and by whom.
That is the honest answer to the head style question, and it is worth writing down properly, because “which head should I order” is probably the most common quote-stage question we get after voltage. This covers the 22 mm and 16 mm operator heads on our XH2 and LA135 ranges, all type tested to IEC 60947-5-1. ACXION builds all three styles, so read this as a manufacturer talking through its own catalogue rather than an independent survey.
What the head decides before any electricity flows
The head is the part your operator actually meets, and its shape settles four things at once. How much of a gloved finger it accepts. Whether a sleeve or a passing carton can catch it. How far the contact travels before it clicks. And how the sealing stack between head, bezel and gasket comes together, which is what keeps water on the right side of the panel.
Change the head and you change all four. Which is why the head style belongs on the order as a conscious choice rather than whatever the last panel had.
Flat heads, and the doors that get wiped down
A flat head sits flush with the bezel, and that single property drives everything. Nothing projects, so nothing snags. Wiping the door becomes one sweep across the row. Not twelve small circles around little islands. Panels that get washed want flush. Cramped cabinets want flush too, where every millimetre in front of the legend counts. It is the sensible default in both.
Gloves are where flush pays for it. A flush surface gives a thick glove nothing to grip. Watch a cold store operator for a minute and you will see him pressing with a knuckle. Marking is the second trade. A flat head leans on the legend plate, which reads fine straight on and poorly at an angle.
Raised heads, for gloves and for glow
Raise the head proud of the bezel and the glove problem largely goes away. Now there is geometry to press against, and the click reads through the glove. Illuminated versions gain as well: the raised lens throws colour at an angle, so status reads from across the workshop. That is why start and stop duty overwhelmingly wears raised heads.
The tradeoff is the snag. Anything that projects can be caught, by a sleeve, a lanyard, a forklift mirror that got closer than planned. Doors where people lean across the controls holding tools? Then it is a real failure mode, not a textbook one. Row spacing deserves a second look with raised heads. The extra height changes how fingers land when two functions sit close. The catalogue spacing figures already assume some head mix, but a door built entirely of raised illuminated heads deserves the numbers checked rather than assumed.
Mushroom heads, palm operation and the one you cannot avoid
The mushroom head signs a different contract. It swaps precision for certainty. A palm lands on it from any angle, in any glove, without looking. On emergency stop duty it is not a style choice at all, the standard expects a direct opening action and a head that can be struck, which is why the e-stop corner of every panel ends up wearing one. Our 1 bouton-poussoir momentané à tête champignon 1NO exists for exactly that duty on the XH2 platform.
Elsewhere the mushroom earns its place on repeated palm operation, jig loading stations, cycle start on a line where the operator’s hands are full. Its weakness is accidental actuation: a broad head collects elbows. If bumps are the risk, the fix is a guard or a shroud. Shrinking the head to dodge elbows throws away the reason you chose it.
Legends, colours and the marking underneath
Head style and marking are one decision. Making them separately is how panels end up with handsome heads nobody can read. Flat heads lean on the legend plate below them. That suits engraved or printed rows where every function gets labelled the same way. A raised head carries marking on the cap itself or in the lens, which reads faster from across the aisle but offers less room for long names. Illuminated lenses narrow the palette further, because the colour is doing part of the talking. Red and green on start stop duty, blue for a function that must be distinguished, and white or neutral for everything else. Panels that ignore this end up relying on position memory alone, which works until a new operator arrives on a night shift.
Colours and illumination interact, and the interaction catches out nearly every first time buyer. An unlit green lens reads as dark grey under sodium light. A lit one can drown its own legend if the marking sits under the LED instead of beside it. The cheapest insurance is a sample unit on the actual door, under the actual light, before the whole row is ordered.
Side by side
| Head style | Reach for it when | Attention à |
|---|---|---|
| Flat | Washdown doors, tight cabinets, clean rows of identical functions | Thick gloves, angled legend readability |
| Raised | Gloved operation, illuminated status read from a distance | Snag risk on doors people lean across |
| Mushroom | E-stop duty, palm-operated cycle start, hands-full stations | Accidental actuation, needs guarding on busy doors |
The full option matrix, head by head and contact by contact, sits in the catalogues on the downloads, and it is worth a look before the row is finalised.
Two practical notes that cut across the table. Mixed rows are normal and correct: an illuminated raised start next to a flat reset is a coherent panel, not a mistake, as long as the spacing rules hold. The style choice also interacts with the mechanism under it. A raised head on a latching mechanism behaves differently from a raised head that springs back, and the Bouton-poussoir à tête surélevée à verrouillage 1NO1NC and its momentary twin share a footprint precisely so that choice can be made late.
If a door’s duty is unusual, describe it to us in one message through the contact and we will say which head we would put on it, including the occasions when the answer is the one you did not expect.