Antique Nickel Plate finish over steel. Also known as 'Chicago Screws'. Cap head diameter - 11mm Two part post and threaded screw. Sold in Packs of 10

Use a 5mm diameter drive/hole punch - 3777-07.   

Threaded screw with rivet style smooth cap, ideal for fixing together layers of leather for cases, straps, axes sheaths, sample cards and more.
The screw fixing allows for the screws to be removed and re-attached, for a more permanent fixing add a drop of superglue to the thread.
The post length dimension will give the minimum leather thickness the post will go through.