Young man brought me the front wheel off his fixie because he was having problems with the hub.

Turns out it was too loose for too long. Cones badly pitted and axle notched.

Need new axle set. No identifying marks on wheel. Boy thinks it was a "Jetset" brand wheel.

The axle set seems quite generic. Bolt-on, 9mmx140mm

How can I order an axle set an be assured that it would work? Thank you.

This will most likely work, at worse, you'd have to modify or not install the shields. I would take the cones and lock nut from this one, and use on the existing axle, alternately, you could get a Q/R lever.
Wheel Master Front Hub Axle Set - FM21, M9 x 108mm, Quick Release

Typically, separate cones are 3X or more the cost of this whole axle assembly.

Use a good water resistant grease, I like boat trailer wheel bearing grease, fill up the cups, put the new balls in, cover with grease, assemble, tighten, wipe off excess grease.

If the cones fit, and are the same on both sides, things will work okay; different cones may cause a slight change in where the balls are tracking on the cup.

The shields typically pop right off (set in a socket) and if the cones are the same OD can be swapped

The cones seem much deeper (thicker?) than the original and the shields much further outboard.
the existing axle, like the cones, is toast.
Do you gents think this one would work? Appearance is about the same as original;
Shimano XT HB M737 Front Axle Set (039750025700) at CambriaBike.com

There's no real positive way to order the proper parts by guess.
We can't really guess better than you can.

Have you stopped by the LBS to see if they had some "generic" sets?

I've bought various "generic" parts here, mostly BB spindles of assorted sizes. You might do the same with axle sets.

Husky Bicycles: Hubs & Axles

Well,I'm throwing in the towel and telling the guy to check with lbs's. Good idea about stocking misc axle sets.

Seems like a few years back there was some outfit on the internet that carried all these axles and they had a diagram showing what measurements to take on the one you wanted to replace, and then you could select exactly the right one. Anybody else remember that?

I remember how to measure things.. I learned that in the 1950's..

That's good, Bob.

This is a place Wheels Manufacturing, Inc. that sells axle kits if you have the meansurements you need. Roger

Looks like just from a photo that the old axle is a bolted type and all the replacement ones mentioned have been QR hollow axles. I'm sure that the hub could be converted if the owner wants that, You'd need a skewer too then.

A caliper, or even a ruler is your friend. Guessing is just guessing.

If your guy brought the old axle into an LBS they can find a suitable replacement in a snap. Then it is either have them install it into the hub, or he can bring it back to you. Most likely there will need to be some fine-tuning of spacers/washers to get back to the original OLD to match the fork.

So, what's wrong with re-greasing and putting back together?

Did you LOOK at the photo of the cones and axle the OP posted?

Zoom in on the cone on the right at the very top of the race channel and check out the pocking. That's not even pitting, that looks like a line of arc welding laid down by a blind man.

It wouldn't last long like that before it was just as bad as it was when the kid brought it in, it's likely it would ruin the hub as well the second time.

Just fabricate a replacement. Pretty simple. Problem solved.
Cheers,
David in Alaska