flange nuts

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

gld

Well-Known Member
HMEM Supporting Member
Joined
Jun 18, 2009
Messages
176
Reaction score
89
Location
Tarkio, Missouri
4-40 non serrated flange nuts







Would any of you fellows happen to know of a source?

I’ve spent the last week surfing the web. Got a lot of hits, but no one seems to have. One company in the UK has them in metric. Sent e-mail enquiry about 4-40. No response.
Sent e-mail to Micro-fasteners, no response. No response from one other company in California. Oh, and I need them in stainless steel.


Looks like I may have to make them. 64 of them. yuk .
 
When I wanted some, I too could only find serrated ones. I made a small threaded mandrel and turned the serrations off on the lathe. A quick job provided you are not talking hundreds! (64 shouldn't take too long, also has the advantage of ensuring that the face is dead square to the bolt.)
John
 
Last edited:
Amazon has them, roughly same price. Looks like the tiny size is just not used much; bigger ones are reasonably priced. Consider buying next smaller metric thread and rethreading, if you can find metric in stainless at a reasonable price. Otherwise, yep, looks like either 200 bucks worth of fasteners or make 'em. If you've got CNC capability, run in batches of 25 or so out of 303, shouldn't be too awful. If not, one at a time, no fun even if you make a jig and batch 'em.
 
At $3.20 a quantity of 64 is a bit of change. Yet to machine them one at a time out of solid round stock, would likely take 30 minutes each, thats a tedious week.

I would suggest you cold head these, likely how the factory does it. First buy a 6 point deep socket the size of the hex. A chunk of tool steel, Fit the socket tightly into the block, machine an area to be the flange, make a stop that sets the depth of the hex for the nut.

Cut off a piece of SS hex stock, and a 30 oz hammer, two wacks should do it. Use a hex collet to hold the nut face off, drill tap.

Likely do the lot in a couple hours or less.
 
hi forgive me for bin a bit thick is it standard 4mm thread you looking for
and do they need to be SS
 
Hi there,

Aren't they Aircraft 'K' nuts, should have thought you'd pick them up over there from any airfield maint shop..

Chris
 
Do You have a way of indexing? 30 minutes a piece, not here. Do them 2 at a time.
1- plain stock in a 3 jaw chuck.
2- turn outside of flange diameter.
3-plunge outside of hex diameter 2 flange thicknesses + width of cut off tool.
4-put in indexer and mill the flats.
5-back to lathe to drill, Tap, and part off.
6-2 parts done.
Could even do 2 or 3 sets at a time off of the bar, if Your so inclined.
 
I found them. Waaaaayyyy over my budget.


But can you make them cheaper? Even if your time isnt an issue, you still need to buy stock, end mills, taps and drills. Doing all of this in stainless will not be any fun at all, especially at 4-40 size. Id be really surprised if you got 64 done without a tap replacement or two.
 
Well gentlemen thanks for all the tips and advice but I have decided to make them. I puttered around in the shop today and made 10 among several interruptions . One being an hour and a half nap after lunch plus a 2 hour visit with a friend who stopped by.
I have a 6 foot piece of quarter inch stainless steel bar that was ordered by mistake several years ago. I started out by cutting off to 3 inch pieces. Each piece was put in the lathe, squared the ends and drilled about a half inch deep for the threads. Then over to the mill in a hex collect block to do the hex. Then back to the lathe to part off.
After parting off they were chucked in the lathe by the flats and the threads cut.
A trial fit showed the .250 OD of the flats to be a perfect fit. That will work for 32 nuts.

The other 32 will require a smaller OD. So after the first batch is finished, I’ll have to experiment to see how small I can make-em.

These are 3/16 across flats, flats are .065 thick, flange .031 thick.





I didn't work real fast on these. About 3.5 hours.
 

Latest posts

Back
Top