There's a company (US Micro Products) that makes a metal kiosk KB with MX blacks in it.
Interesting. I guess the ones I felt had worn in MX Blacks.
A year ago, I had a job interview at a company that made kiosks and got to try their equipment. They used MX Browns for the keys, and MX Blues for the trackball's buttons.
Using MX Blues to simulate a mouse click -- interesting.
I saw one of these at the airport last time I went. Felt like blacks.
I would also guess mx blacks. Many commercial Cherry boards use them.
Could be very worn in Blacks.
You might find something of interest here:
http://www.dskeyboard.com/steel-keyboards
Their website is a bit light on switch information, and they'll only respond if they're in the mood — Kurk got some information out of them, but evidently they don't like me as they've ignored all my e-mails. (Sadly it's generally only Taiwanese companies who actually respond to anyone.)
Thanks for the link. I did some brief searching before making this topic, but I didn't find a company disclosing what switches were used in these industrial kiosk KBs. The company you linked claims that the keyboard uses "Carbon contact-technology". I've seen some other sources claiming "Carbon-Gold contact technology", which led me to think that it doesn't use Cherry MX switches, as the contact points are gold and silver.
Dug a bit further, and DL'ed the Spec sheet of one of the keyboards, and I found this:
Anyone know of any switches that use a silicone switch pad with carbon contacts? Also, why carbon?
Just because the keys are low profile, doesn't mean the switches are 
You're telling me that the switches are already pre-depressed by ~1.5mm?
Speaking of which, if some kiosk keyboards use Cherry MX switches, wouldn't that make the actuation at the very top of the keypress, due to the low profile?
It's been a while since I last touched a kiosk keyboard, but the ones I've used didn't seem to have the actuation at the very top. I guess the ones I've tried used "silicon switch pad with carbon contacts"
