How are set screws made?
How are set screws made?
(OP)
So this is something that I have been curious about for a long time and never figured out. When you use a metal or plastic set screw, they can have a hex recess for an Allen wrench. How is recess this made? I would have guessed that the hex is punched in while the part is just a cylinder. I know that the threads are roll formed so punching the hex head (I think) would cause mushrooming and hinder the thread rolling. Intuitively, it seems that machining it in would be way too expensive given the cost of these parts. The metal parts are obviously not cast or forged. Also, is the process different for metal fasteners versus plastic ones? Just something that had been bothering me since college. Sorry if this isn't exactly the right forum but it seemed to be the most appropriate one. Thanks!
-Steris
-Steris





RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
i suspect punching th ehead is the answer. maybe look at a "How is it made" episode on Discovery ??
RE: How are set screws made?
http://www.google.com/imgres?start=235&hl=en&gbv=2...
RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
Thanks for all of the replies. It would seem that cold forming is preferred way for mass production. I thought that may have been the case. Mushrooming really isn't an issue when you have a head on the fastener - I guess I just assumed that since set screws don't have a head then the mushrooming would have prevented cold forming.
RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
There is a documentary, possibly up on YouTube on W.L.Robertson the inventor of the Robertson screw. They do explain how the screws are fabricated, including the Robertson socket. It is cold formed. I don't see why they would fabricate a hex socket any other way.
I do not know how popular Robertson screws are outside of Canada.
--
JHG
RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
I've run into them on occasion, however, the last set of 'accessory bits' I bought for my Ryobi cordless drill/driver came with 3 or 4 different size square-head bits so it's not like they're being completely ignored here in the Colonies
BTW, my understanding is that the Phillips-head screw was developed primarily to enhance the assembly of products via the use of automation, either hand-held power-drivers or full-on automated systems due the ability of the driving bit to 'self-center', and that normal 'civilian' use with non-powered tools was never a driving factor (excuse the pun).
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
RE: How are set screws made?
Regards,
Cockroach
RE: How are set screws made?
Where I work, we use Phillips machine screws here most of the time, and we are very happy with them.
Here in Canada, self tapping wood screws are Robertson. I do not understand how people manage with anything else, outside of Canada. We did ship a system to a customer in California in a wooden crate assembled with Robertsons. We had a good chuckle over that. It was easy enough for them to make a square bit.
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JHG
RE: How are set screws made?
RE: How are set screws made?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: How are set screws made?
RE: How are set screws made?
RE: How are set screws made?
You are thinking of the book One Good Turn, a history of screws in general. I think he was looking for the earliest screwdriver.
--
JHG
RE: How are set screws made?
BTW, I've seen Robertson style screws in places where I suspect they were used to prevent, or at least deter, someone without the proper tools from removing some cover or something. However, recently I've noticed some stuff coming out of Europe using so-called TORX security screws...
...so now I've had to add some additional bits to my collection.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.