I have ordered several faucet handles but every one has been too large, or the wrong shape (square). Home Depot and Lowe's have handles but all too large or the wrong shape. Universal Outdoor Faucet Handle - too large/wrong shape. House was built about 12 years ago. Is this faucet really that rare? I would appreciate your expert advice, this has become frustrating.
I know this thread is old but I found it because I'm having the same issue. I wanted to share what I found for a solution. Hope this helps anyone else out there.
There are a multitude of manufacturers of hose faucets, both foreign and domestic. The handle spline type and stem size is not standard, there are as many sizes and spline counts as there are manufacturers (hundreds, thousands?). As suggested by @WarLoki, try a good local hardware and/or plumbing shop and you may find a variety of a few different ones. You should also begin planning for the (probably) inevitable replacement of the faucet.
Or get one of these crappy universal handles that uses set-screws:
Years ago, most hose faucets/bibs/spigots/valves were manufactured in the good ole' US of A by a few long standing companies, you could get replacements parts for those. Sadly most people do not want to spend a couple bucks more for better quality so we are left with Chinese junk that cannot be repaired, just like one day we won't have any good Mom-and-Pop hardware and plumbing shops because everyone goes to Home Depot and Lowes for poor service, self checkout, and Chinese junk. Sorry to rant... good luck.
In my experience, the issue is usually the stem and not the handle; the stem is usually brass and the knurls get rounded off once the handle gets loose. So replacing the handle doesn't help much. Sometimes you can find a replacement stem, but that's probably as costly as just replacing the whole thing.
For a reasonable temporary repair, I'll epoxy the handle onto the stem, and when that breaks just replace the entire spigot ($20) rather than spend hours trying to match parts.
I had the same problem, all the available replacement handles were too big. I went to a real plumbing supply store, Brother's Plumbing in Sacramento. They measured the spline size, said it was a "1" and sold me a 287-T Tee Handle MFG. by Thriftco Plumbing. It didn't slide on that well, but after I gave a couple of whacks with a rubber mallet and secured it with a #8-32 x 3/4" brass screw, it stayed on and works fine. All my exterior hose bibs were installed 25 years ago, are like this, manufactured in the Philippines, and that is why it probably is tough to find a fit.
The replacement product everyone is looking for is the Nibco T090722 product for small diameter spline faucets. That link takes you to one of the few places, Menards, that still have these, (as Nibco stopped making them probably 8 or more years ago). That's why you can't find them in an big box, small or specialty hardware stores.
I had the same problem and had been searching all over for about a year. I'm SO HAPPY to finally find a small diameter stem replacement handle. Everyone stopped making these several years ago, and I was about to give up and just have the hose bib replaced with a new model.
Of course, the only way to be 100% certain that you have a matching handle, is to use a Faucet Stem & Handle Broach Gauge, but this one worked for me, and just based on the photo, it should work for you too.
The only other alternative is to use a destructive solution such as the Mandle (shown in another post here), or using J/B Weld to permanently cement on a handle that doesn't fit.
Either way you'll have to get someone to come and install a new hose bib when those temporary hacks fail.