Super mallet

Fellow framers- I came across a design for a mallet I'd love to make. It uses cut discs of "pipe blind" as the striking surface. Anyone know how I might lay my hands on some said pipe blind? Apparently it's used to "blind off" pipes for maintenance in industry and it's pretty durable stuff.
Any ideas?
Thanks!
p.s. Here's the article:
<http://www.wkfinetools.com/contrib/pScott/art/mallet/difMallet1.asp>

pps. I'm planning to make one for me and one for the western auction..

Chris,

http://www.mcmaster.com/#pipe-blinds/=ahq6bu

My source for anything industrial.

You could also try MSC or Grainger.

Thanks Gabel, I use McM-C quite a bit too, great source.
Their pipe blinds are steel and stainless: this guy uses a synthetic material, in sheets, and makes his own rounds.
Grangers are too pricey (by the piece).
Think I'll try the local plastics company.