1/4-24 thread history

[Gomer]

I was pondering this and have never seen anything in writing how The Motor Company came to use this on thier motorcycles.

Standard of the day?
Proprietary, Indian stuff won't fit?

Just something to think about over the Holidays.
Interested in the take on this.

[Paps]

Application is usually the reason for thread design decisions. I said usually. Keeping the consumer from scoring hardware elsewhere is another reason. Paps

[LouieMCman]

There was no standard tread sizes back in the early days and most factories made their own or had someone make them.

[knuckleheadtim]

I think there is a was a very logical reason for the 1/4-24 thread. A coarse thread is prone to loosening from vibration, while a fine thread strips easily in aluminum. The 1/4-24 is a good compromise.

[bmh]

The 1/4-24 thread was actually used a fair bit back in the early days. One application I know of is Klaxon K-22 horns as used by Duesenberg and others as well as some old Delco horns employed that thread. It is listed on most good tap drill charts along with other special use threads such as 1/4-40.

[Jerry Wieland]

Prior to WW2 there was no SAE/SME standards and manufacturers made their own fasteners.

WW2 was the first time in history that Chevolet engines made in Detroit were put into Dodge trucks made in Cleveland using Ford brakes made in Windsor and all assembled in Sacramento. The nightmare was unbelievable and it soon dawned on people that standards needed to be implemented and enforced.

SAE/SME standardized everything from oils, bolts, measurements, frame widths and more.

Jerry

[Paps]

Prior to WW2 there was no SAE/SME standards and manufacturers made their own fasteners

SAE/SME standardized everything from oils, bolts, measurements, frame widths and more.

Jerry

This is true but thread designs were still based mainly on application. The first machinery handbook was published in 1914. In its' index you will find •SCREW THREAD SYSTEMS AND THREAD GAGES •TAPS AND THREADING DIES. This first edition of the machinery handbook is an accumulation of 100's of years of machining and mechanical trial and error and know how. Few of us realize just how far back this knowlege goes. The first steam engine alone was designed, machined, fabricated, and assembled, in the 1700's. Standards, as Jerry mentioned, were neccessary in the case of war but in the civilianized private sector, bastard threads generate continuious revenue to the original manufacture.

[exeric]

If you wikepedia SAE you will find that it goes back to the early 1900s, but I think standarizaation of fasteners goes back even further. If you remember Eli Whitney from history class as the inventor of the cotton gin. His biggest contribution was in gun manufacture and the fact that his gun parts were interchangeable. From my own experience, I have never come across fasteners from early motorcycles that were different from modern fasteners. The only difference is; early fasteners are usually made on automatic screw machines and they look much nicer than modern fasteners that are cold headed and thread rolled. As for 1/4-24 fasteners; they are standard but just not common. Harley and Indian strictly adheared to SAE standards from the very beginning but every manufacturer is entitled to make proprietary parts so long as they follow accepted engineering standards.

[flat-happy]

i remember reading an article on the 1/4 24 thread one time.the article stated that in the early days manufacturers knew that 1/4 20 was too coarse and would come loose from vibration and it was known that a new thread system was needed. henry ford was credited {according to the article} with coming up with a new system and tried unsuccesfully to sell it to american automobile manufacturers and eventually sold it to the brits where it became known as an "english" thread and 1/4 24 was part of that system as well as the smaller bolts that hold the aircleaner backing plate to the old linkerts. i don't know if there was any truth to that article or not but SAE was adopted about that time