Push Button Switches
ALX-HB4-BC42 Mushroom Head Push Button Switch | 22mm 40mm 1NC
22 mm mushroom head push button switch with 40 mm red cap and 1 NC contact, momentary spring return, zinc alloy chrome bezel, screw terminals, 600 V AC 10 A. OEM supply from ALUX.
The HB4-BC42 adds a 40 mm mushroom cap to the HB4 bezel. The larger face gives an operator a target that can be hit with the palm or the back of the hand, which is why this shape is chosen for stop and fault-reset functions on machinery. The contact is normally closed, so the circuit is made until the button is pressed.
Technical Specifications
Item | Specification |
Mounting hole | 22 mm (22.3 mm cutout) |
Bezel / head material | Zinc alloy, chrome plated |
Contact housing | Plastic |
Contact configuration | 1 NC |
Operation | Momentary, spring return |
Actuator | Mushroom head, 40 mm dia. |
Actuator colour | Red |
Illumination | None |
Rated voltage / current | 600 V AC, 10 A (AC-15 duty) as marked on the contact block |
Termination | Screw terminals |
The 40 mm cap fits the standard 22 mm bezel and cutout. For a larger target see the 60 mm HB4-BR42 group; for a maintained version see HB4-BS442.
Design Features
- 40 mm mushroom cap: a palm-sized target that is easier to hit under gloves or in a hurry than a flush button
- Normally-closed contact, so a broken wire or a loose block trips the circuit rather than hiding the fault
- Zinc alloy bezel with chrome finish and a metal clamping ring, sized for panel steel up to the standard 22 mm nut
- Contact block clips on from behind and releases without removing the bezel, keeping service work off the panel front
- Cap, bezel and contact block are separate parts, so any one of them can be replaced on its own
Model Options
Model | Cap diameter | Contact |
HB4-BC42 | 40 mm | 1 NC |
HB4-BC21 | 40 mm | 1 NO (black) |
HB4-BC31 | 40 mm | 1 NO (green) |
HB4-BC51 | 40 mm | 1 NO (yellow) |
The 1 NO versions (BC21/BC31/BC51) use the same cap and bezel and differ only in the contact block.
Applications
Machine tools, conveyors, mixers, press and forming equipment, woodworking machines and any panel where a stop function has to be reachable with the palm.