Bit History: The Spanner

This is the fifth article in our ongoing series of posts on the history of screwdriver bits. We’ll be posting one a day leading up to the launch of the Manta Driver Kit and Mahi Driver Kit on Tuesday, April 24.

After over a couple years at iFixit, I’ve reviewed hundreds of community-contributed repair guides for just about every type of small household electronic. Which means I’m pretty familiar with the different ways they’re held together. More often than not, appliances still use the old, familiar standard: the Phillips. But about a year ago, a group of students in iFixit’s technical writing program were puzzled by some unusual screws they found on a Breville Juice Fountain Plus.

They’d never seen them before—and they didn’t know what the screws were called. So, they asked me.

Spanner screw on a juice fountainSpanner screw on a juice fountain
The thing is, I didn’t know what they were called, either. I spent a few minutes Googling things like “split flathead screw” and “screw with two dashes.” Then I struck Google gold with “screw with two slots.” Turns out, a slotted spanner screw guarded the entrance to the students’ well-secured juice machine.

You may have heard the term “spanner” used for wrenches before, but it also refers to security screws with multiple pinholes or slots on the screw head. The pinholes and slots act like a lock. A specific bit is required for removal, making them difficult for hooligans and ne’er-do-wells to tamper with. (You also can’t jam a common flathead into the screw to turn it, as you might with a pentalobe or security Torx screw.)

spanner screw variations
Spanner three hole, two hole, and slotted images by Frank C. Mueller, CC BY-SA 4.0, via Wikimedia commons.

Those distinctive pinholes have earned the spanner a few unusual nicknames, including the Pig’s Nose and the Snake Eyes. And while I think the screw looks a little comical, some companies actually prefer the spanner screw for its unique, minimalistic aesthetics. Leica Camera company, for example, used spanner screws on the knobs of their rangefinder cameras back in the 1950s. And their minor popularity continues to this day. Spanners are utilized frequently enough in electronics to warrant spots in both our Manta Driver Kit and Mahi Driver Kit.

When it’s not holding juicers or vintage cameras together, the spanner is also commonly used to discourage vandalism of public property and keep things like highway signs, restroom stalls, and elevators intact.

In fact, the two-pin head type can be seen on the iconic signs of the London Underground. I even found a slotted spanner in the bathrooms at iFixit, guarding the soap dispenser from any potential thievery. The matching driver (which came with the dispenser) functions like a rudimentary key.

Spanner screws on the London Westminster Underground sign
Too bad spanners don’t protect against blobs of sticky gum, which you can also see on this photo. Image by Oliver Deisenroth, CC BY-SA 3.0, via Wikimedia Commons.

If you’re wondering when this security screw came to be, your guess is as good as mine. The screw-type was common enough in 1945 to bear mentioning in a Naval Tool Manual. So they’ve been around for at least that long. And based on their relative ubiquity, it looks like they’re here to stay.

The next time you’re out and about—be on the lookout for this fantastic snake-eyed, pig-nosed screw. And tell us any unusual places you’ve spotted this screw head in the comments.

While you’re here, check out our previous posts on the Flatheadthe Robertsonthe Phillips, and the PentalobeAnd be sure to join our mailing list—you’ll be the first to find out when the Manta Driver Kit and Mahi Driver Kit drop on Tuesday.