What is the Danco Flat Washer 2-1/4"X3/4"X1/8" made of?

The Danco Flat Washer 2-1/4"X3/4"X1/8" costs$6.31 (for 5). You can purchase it here: http://www.buyhardwaresupplies.com/?t=5&itemNumber=4079919.

Flat washers come in many different s and are dividedinto three series: Narrow, Regular, and Wide. For a complete list of s,check out this website: http://www.engineersedge.com/plain_washers.htm

The different types of flat washers include: • Fender washers• Type A washers• Type B washers• Nylon washers
You can find more information on these types of flatwashers on this link: http://www.ehow.com/list_6516551_types-flat-washers.html

Different flat washers are made from different materials.Those materials include zinc, stainless steel, carbon steel, different types ofrubbers, and plastic.

Flat washers are most commonly made of steel; however they can be found in a variety of other materials such as brass, silicone bronze, chrome and rubber.

Flat washers are thin round pieces of metal with a hole through the center that are used to spread force under a bolt head/nut.

I would try to find a 3/8 to 1/2 NPT adaptor on Amazon.
If Danco has a website, it's likely that the instructions for your model are available in the support section of the website.

there is never a fiction ring at the washer end, sometimes there is a cup shaped part that holds the washer but nothing else so it must be intended to go around the stem

Is it brass, stainless, plastic or rubber? I think a stainless one might be for the knob screw, I don't think there is one inside, it might just have fallen into the pack. We get weird stuff all the time that doesn't belong. Hope this helps.

Danco is an aftermarket supplier of plumbing repair parts for almost all major brands. Look for a danco part that looks like the part you need then check the "compatible with" list on the package.