9 Pieces 5/16 Knob, M8 Star Knobs 5/16 48 mm Diameter, M8 Threaded Knob Galvanized Carbon Steel, Quick Detach Knobs with Through Insert for Clamping Fixtures and Holding Devices

Value and I had more than what I needed for backup. Very good quality for the price.

They really shouldn’t state 1/4-20 anywhere, these are definitely metric M6. That said they are well constructed and an excellent value.

I just need some to replace a few off several studio background lights stands. The kit had all I needed and then some.

These are not 1/4 X 20. They must be metric and the don't fit. Dang Chinese junk.

These are metric M8 size, 5/16” bolt does not fit

Knobs were exactly what I wanted expect the knob itself is smaller than I expected. They are exactly the size described I just did not pay enough attention. They serve the purpose I need (fence for router table) so I will still use them.

The description of these star knobs is confusing at best. I wasn't sure if I was getting 3 different sizes, imperial or metric, or what. I figured I'd take a chance, I can always use more knobs!Turns out the ones I received were all one size, M6, which I'll live with, but disappointed because all my other jig fixture hardware is imperial. So now I'll have these oddball metric ones in the mix that I'll need to get an assortment of hex- and tee-nuts for.Otherwise, they are a quite nice low profile design, and will come in handy often. Well made and seem sturdy - I cranked one down as tight as I could get it by hand and it held up without complaint.Gave only three stars due to the poor description.

I got these for making jigs and fixtures for woodworking. These are metric and take a M6 machine screw or bolt. Most US hardware for jigs and fixtures, like T-track, is imperial/SAE so you will need to test your metric bolts and nuts to see if they are compatible. For reference, M6 is 0.236", or about 1/4".The knobs themselves are nicely made with brass threaded inserts. Although the backs of the knobs are hollow, the knobs are not flimsy so I don't think that will pose a problem. The through-hole design allows the knob to fit over a long bolt. Alternatively, you can thread a M6 cap screw in through the top with a little bit of epoxy or red thread locker and convert the knob to one with a threaded stud of your choice of length. The depression in the face of the knob measures 9.6mm in diameter, but M6 cap screws have a nominal 10mm diameter head.The cap screw I had on hand measured 9.78mm in diameter and I was able to get it fully seated without any visual distortion of the knob. This makes for an excellent knob with stud.Tip 1: if you want to make a knob with stud and the head of your cap screw is too big for the hole, you can reduce the diameter of the head slightly by chucking the screw in a drill and use a file or belt abrasive to make the head narrower. Alternatively you can drill out the hole if you have a 25/64" drill bit. A bullet point or brad point bit works best.Tip 2: Metric cap screws are typically fully threaded only to about 30mm so if you need something longer, be prepared to a accept a partially threaded shaft or use a section of M6 all-thread and epoxy or red thread locker.