1970’s Audemars Piguet “AP Steel” Automatic ref. 4010, Black Dial

Up for grabs is an Audemars Piguet Octagonal watch

A rare and unusual reference 4010 with cal. K2121 automatic movement, in steel

B37 serial is unusual as its only 2 digits after the letter series. There are other examples (if you look enough) with similar 2 or 3 digit serial numbers for this model, indicating to me that very few were made overall.

As you can see, the caseback is signed ‘AP Steel’, specifying it proudly. Traditionally, most integrated bracelet watches are made in precious metals. So, Audemars made it a point to specify this is a steel model, assuming to tap into a lower price range customer base who wanted a dress watch, but perhaps couldn’t afford or didn’t want to beat up a precious metal counter-model.

Another unusual detail is the size. During this period (and with dress watch models in general) we see these in smaller size, almost mid-size by today’s standards. However, this watch features a substantial 35mm wide case, which shows up nicely on even the larger wrists.

The matte black dial looks super sharp and attractive with contrasting white print and specification on “Automatic“. Another sign that AP made this watch to be worn more regularly than your typical manually wound.

We’re not done with irregularities yet. Now comes the bracelet. Its a steel bracelet with woven design, but wait, it also has removable links! That’s right, you don’t have to cut this bracelet to make it fit. Just add or remove some links as you would with any “normal’ watch. The AP logo has been damaged on this one, but it is indeed an AP made and original bracelet.

There are no box or papers for this piece. No service history, though there are a few service markings inside the caseback. It currently shows -8 seconds with ~320 amplitude on the timegrapher.