Most all 3/8" NC nuts take a 9/16" socket or wrench, do they make a 3/8" NC nut that will take a 1/2" wrench or socket? If so, have a name for it or a part number? Thanks!
I think 12 points do https://www.summitracing.com/search/section/nuts/thread-size/3-8-16-in/nut-style/12-point Or you can drill and tap a 5/16 nut. Oops, the 12 points take a 7/16
I've used a flap disc on an angle grinder to mill off some meat from a bigger nut to make them smaller, takes a bit of patience but if you only need a few it's not too bad. Would suck if you needed like 50 though.
I have gotten some 3/8-16 rod couplers from time to time that were 1/2" across the flats at my local hardware store. I was not seeking them out so I could not say were they come from or who makes them, but they are made at least in a rod coupler form. A guy could cut or part them off on a lathe if he really has to have them without having to drill and tap some hex stock or a nut. Not sure of your situation but seems like a lot of effort for a 32nd on each side.
Paul, Got up this morning and Tacoma Screw was the first call I made only to be informed they are a construction orientated company (not automotive) BUT if they had a part number or "name" they might be able to help........................ All of you have given me some great ideas, Thanks!
If those can have a 'washer' forged onto the bottom, they are called "USS Aircraft flange nuts". I've seen them in standard and SAE thread, 3/8" bore and 1/2" hex. A while back, though...
https://www.albanycountyfasteners.com/Flange-Nuts-Serrated-316-Stainless-Steel-p/1063-100000.htm Maybe these will work.
Paul was close about the headers, need 6 nut's for a real tight fit header collector. Since I only need 6 I will be using KJSR advice and drill & tap a 5/16" nut. Mike & Sam, Don't think I have enough room for the built in washer base type nut but good info anyway. Thanks again!
Couldn’t you machine the flanged washer down,you would only need to take off enough to clear your header tube and still end up with a partial washer as such. Just a thought.
Why not use fine thread 12 point bolts and "K" (or Jet) nuts (reduced head size with flange). The nuts are self locking and if they do come loose they are not going to spin off the bolts as quickly as if you use "fast" bolts (race car builder definition of coarse thread fasteners). IMHO coarse thread bolts/studs should only be used in tapped holes in castings/soft metals. Roo
I'll guess that a 5/16 nut drilled with 3/8 - 16 coarse thread will fail. The cut (Thread) is too deep and the height is shorter so there's less thread engagement. Equal torque on less threads is not going to make anyone happy. Fine thread would be about 10 times better and a deeper (taller) nut with more threads would the best you could hope for. There's at least a dozen ways to connect a header collector to an exhaust pipe, the 3 bolt flange being about the worst. What sort of manufacturer doesn't allow for bolt clearance in their flanges anyway?
How about roll-your-own out of a piece of 1/2" hex stock, drill and tap for 3/8", then cut to size? Being header nuts, you could make them out of brass stock.
No problem! If you do cut threads in plated steel nuts you'll be removing the corrosion protection. I've done them in brass and stainless as well as zinc plate.
Vicky Of coarse you know this Tap drill for 3/8-16 is actually 5/16" so worst case scenario is a very slight "hint" of the 5/16-18 thread showing (very slight), unless the original minor diameter was too big. The key (to any size) is a tap drill that is sharp and sharpened evenly so as to not cut oversize.