Hamilton Beach mixer model 60600

I do not think it matters the plastic disc may be to keep beater fro mixing bowel. i would try it and see what happens, you could switch holes after trying it.

Is this model 21 for sale on eBay the same one you need a part for?

For such a low price, you could buy it, and use it and have spare parts for the future.

https://www.ebay.com/i/113048805687?chn=ps

One of the pictures shows 21.

Hamilton Beach Chrome Model 21 Stand Up Mixer 10 Speed with Beaters and...

Go on line and Google manuals

Replacement beaters may be ordered online from the following site:

http://www.abtecparts.com/proctor_silex_hamilton_beach_mixer_beaters.htm

Check on eBay. Sometimes you will find replacements--even new ones. You'll need the actual Model Number off the tag on your mixer (see link where to find that info).

Search Now for Replacement Parts Accessories HamiltonBeach com

Then search for:

Make Model replacement parts

Either you don't have a Hamilton Beach or, your beaters originally had a center bracket. They only made 2 styles of beaters for their stand mixers, short shaft & long shaft. They both had a buton on the one beater to turn the bowl. The portable mixers aren't joined but, they don't have the button either. I did their factory service for a few years (back in the 70's & 80's) and I never saw single beaters with a button.

Model H was discontinued in the 70's. You might find beaters either directly from Hamilton Beach or on Ebay. There aren't many small appliance repair shops any more, everything now, is considered disposable.

Call the factory. they will point you in the right direction. number online!