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Where to find 1/4-24 and 5/16-20 bolts?

borne2fly

Hot Rolled
Joined
Feb 7, 2008
Location
California
Antique sizes, so I'm told. Not sure if they're still made anywhere on planet Earth except for a few specialty Harley shops, and then only in the one or two lengths used by pre-war Harleys. Does anyone know a source for these odd threads? And no, they are not mis-identified metric threads. These are the real thing, square heads and all.
 
I think you're going to need one of those places - what are they called ?... oh yeah a machine shop;)

There is tap & die company in the US that does the oddball sizes but I can't recall their name.

Only few req'd ? - single point them.

Up to a few hundred - get a split solid die.

Few hundred plus - get a set of dies made for a geometric die box.
 
I have both a ¼-24 and 5/16-20 tap that are yours for the asking.
If for nothing else you can use them to chase threaded holes.
PM me if interested.

Joe
 
drill and put a helicoil or whatever you prefer in there for modern bolts. for the 5/16 you might even get away with just chasing with an M8 tap, depends on the thread depth i guess. M7 might work for the smaller one but i don't think that really exists in the real world...

but then as Gordon said, without knowing your intended use the above may as well be totally useless...:confused:
 
Joe21 .... PM sent

Sorry folks, the only reason I mentioned Harley was that it's one of the few things I could remember that used these fasteners. My application is for toolholders on a turret, and the existing bolts appear to be just mild steel. Yes, I could single point them, but first I thought I'd check if anyone still cranked them out by the truckload, in which case it would make more sense to just buy a bunch. I haven't reached the point yet where I'm too cheap to buy nuts & bolts :) But I guess these really are rare as hens teeth so I'll just hammer 'em out myself.
 
That's true, I'm free to make better ones. Ideally I'd like to make them all Allen heads but I don't have a rotary broach, at least not yet. Dear Santa ......
 
Joe21 .... PM sent

Sorry folks, the only reason I mentioned Harley was that it's one of the few things I could remember that used these fasteners. My application is for toolholders on a turret, and the existing bolts appear to be just mild steel. Yes, I could single point them, but first I thought I'd check if anyone still cranked them out by the truckload, in which case it would make more sense to just buy a bunch. I haven't reached the point yet where I'm too cheap to buy nuts & bolts :) But I guess these really are rare as hens teeth so I'll just hammer 'em out myself.

How hard are the tool holders? Do you have room to drill them out and tap them to a source able thread size?
 
Buy long (short thread long shank) Allen headed bolts, cut off threaded section & rethread to spec.

Hadn't thought of that. I like it. I do have a few stainless Allens floating around, and as I recall I had to modify the heads for something else and they were relatively easy to machine.
 
I had to make a few 1/4-24 nuts a while back for a 1920s Indian Motocycle (not a typo) transmission and was able to buy a tap from Missouri Tool in Fenton, MO. Indian also liked 12-28 screws. These were common sizes at one time but fell out of use. It wouldn't be worthwhile for the few you need, but sometimes a Geometric chaser can be opened or closed to the next size, like going from 8-32 to 10-32. I didn't try going from 10-24 to 1/4-24 because I needed nuts for existing studs, not bolts. AFAIK the thread shape is standard Americano or so close to it that it doesn't matter.

Bill
 
Bill,

A friend of mine is into older bikes and bumps into that problem all the time. He keeps a pail of weird nuts & bolts that always seems to contain the odd bits he needs. And it never seems to run out no matter how many parts he pulls out of it, I swear it's like watching the Sermon on the Mount, I'd like to know where to get a bucket like that :) I've suggested (as others in here have) that he replace all the antique threads with modern ones, but his customers are rabid purists who would go ballistic at the mere mention of such a desecration.
 
I have this theory about bolts.

My theory is that because of regulation and taxation we have no diversity of bolts. The problem is that the more you tax people and regulate them the higher the bar of profitability is for a business. If you increase taxes, its the barely profitable businesses that close their doors.

What this means is that not only businesses, but products have to become more and more profitable in the face of increasing taxation and regulation. For example, I could not get a spring scale at a fishing shop recently. Why not? Because "I would not make any money on it" was the shopkeeper's answer.

Because of this we have fewer and fewer supplies of bolts and less variety of bolts every year.

On the other hand, I looked in the Sears catalog of 1912 and the selection of bolts wasn't that great either, so maybe the theory is wrong.
 
jscpm,

Since you have interjected politics into this, I have to call you out.

"If you increase taxes, its the barely profitable businesses that close their doors."

If you do not make much IN PROFIT, you do not PAY taxes. You lie or you are ill informed. You do NOT pay taxes on GROSS income, just what you get to keep as profit.

You are as ill informed as most of the other one man operations who consider themselves to be "bidnessmen". IF you are making as MUCH as 40 grand, CLEAR, you are pretty goddamned successful. You AIN'T paying an arm and a leg in Fed Taxes.

The people YOU are listening to are mouthpieces for the multi-millionaires.

How about make a direct reply, as if you know something worth listening to, rather than spouting your bullshit?

Cheers,

George
 
I had to make a few 1/4-24 nuts a while back for a 1920s Indian Motocycle (not a typo) transmission and was able to buy a tap from Missouri Tool in Fenton, MO.

They've changed...... they would have to order that in for sure..... I wanted a die for some thing reasonably common a year or two back, don't recall now, and they didn't keep stock, 2 week order or some such...... Ack....
 
I would give Fastenal a call. Their website is almost useless at times and their catalog does not have an index by bolt size. The people that work their seam to use a different system for looking up parts then we have access to. I have found that they can get their hands on parts that aren't even in their catalog (at a small premium). Their specialty is fasteners and they do carry some things in the sizes you mention. I found these on a quick web search:
5/16"-20 x 7" Hot Dipped Galvanized Finish ASTM A307 Grade A Head Carriage Bolt | Fastenal
1/4"-24 Chromium Steel Bright Finish UNS, Round Adjustable Split Die | Fastenal

Good luck.
 








 
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