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View Full Version : Source for "non-slotted-head" SS Screws?



Jeffw5555
02-06-2010, 10:45 PM
Hello all,

I have a project where i need to find a source for some SS screws with a round, plain head, i.e. no slots or phillips indentations, just a plain round dome. I need them in about a 6-32 thread size, maybe 1 1/2" to 2" long.

I've googled to my hearts content to no avail. It would seem like it would be straightforward to make them in a screw machine, just leave out the last operation, but I can't seem to find a source.

Anybody know of such an animal?

CCWKen
02-06-2010, 11:06 PM
Good luck on that. I've seen carriage screws but nothing quite that small and long. Even rivets that long will be hard to find in that size. You might end up having to make your own. Someone with a tig and good at welding should be able to fill the head of a standard screw, grind and polish. Since they're that long, I doubt they're structural so the heat shouldn't hurt.

JoeCB
02-06-2010, 11:25 PM
Jeff, if you end up making them, read the post "turning a precise diam on small drill rod" on the "third hand board" ... might be a help
Joe B

Jeffw5555
02-06-2010, 11:26 PM
yeah, I looked at carriage screws, but they generally aren't made smaller than 3/16" or thereabouts...

I can get by with using button head socket cap screws from a functional point of view, but having them plain would work out better from an aesthetic point of view.

I need several hundred, which may get to be a thousand, so I have no desire to turn them myself. Especially stainless, I always seem to cut it too slow and work harden it....

CCWKen
02-06-2010, 11:44 PM
Get some SS all thread. Then get a steel block equal to the length you need and drill an 1/8" hole all the way through. Set it on an anvil or flat plate, insert a length of AT with +3/16 proud and burnish a head on it with a rivet set. That's how I made some rivets.

I've got a few chunks of A36 that are 1 1/2-2" thick if you need it.

Bguns
02-06-2010, 11:50 PM
You could thread some SS rivets... They should be able to handle the length...
http://www.rivetsinstock.com/rivet01.htm

krutch
02-07-2010, 12:01 AM
Jeff,
With quantity in the thousand/s I would talk to your local Fastenal Rep. I'm sure they could run off that item. Might be cashy though.
Krutch

deltaenterprizes
02-07-2010, 12:39 PM
Try posting your needs on the Practical Machinist site or RFQ site. A screw machine or CNC owner may be looking for a small job, things are tight now a days.

Your Old Dog
02-07-2010, 12:57 PM
Gee I feel silly. Here I been throwing the ones I get away thinking there was no use for them :D

Mike Burdick
02-07-2010, 01:13 PM
...I have a project where i need to find a source for some SS screws with a round, plain head, i.e. no slots or Phillips indentations, just a plain round dome. I need them in about a 6-32 thread size, maybe 1 1/2" to 2" long....


Since you didn't mention application or strength requirements perhaps something like this would work...

They can be purchased with either flat or oval heads.
http://www.mcmaster.com/#drive-screws/=5psl9m
http://www.mcmaster.com/param/images/nails/flatround.gifhttp://www.mcmaster.com/param/images/nails/ovalround.gif

http://www.mcmaster.com/#drive-screws/=5psl9m

.

Evan
02-07-2010, 01:31 PM
It sounds to me what you need is a stainless steel Monobolt. It is a type of pull rivet that always breaks off exactly flush with the head and is available in a button head style. There is a visible but very shallow ring around the snapped off stem but it breaks off very cleanly.

DR
02-07-2010, 04:00 PM
This could be an easy one.

Buy SS rivets 1/8" diameter by length (I assume you can find them).

Send them to a thread rolling company. Superior Threading Rolling in LA is a place I've used in the past with good results.

They'll centerless grind them down to approx .115" dia and roll the threads. No chucking needed. Perfect threads.

Based on my previous experience the cost would be around $1.50/per in several hundred quantities.

BTW, thread rollers insist on grinding to diameter. It's very important the blank be sized exactly, thread rolls are expensive and oversize stock can damage them.




On edit: Fastener companies used to do specials all the time. Now days most fasteners come from off shore so not quite so easy to get specials. Any screw machine shop could do these, but screw machines shops don't do screws much anymore, they're all cold formed. A shop with a Swiss type CNC lathe could spit these out very fast with minimal setup, they might be kind of pricey compared to the rivet method though.

Toolguy
02-07-2010, 04:08 PM
How were you planning to screw them in with no slot or hex for a driver?

Jeffw5555
02-07-2010, 07:59 PM
I guess I should have given some additional info.

The plain button head will be used as an electrical contact to a measurement device, for occasional use. The shaft of the screw will go thru an insulated post, and a solder lug will be attached under a star washer and nut on the underside. It will not have much torque applied during assembly, just a little more than finger tight, so the slot/phillips/socket is not needed to attach it. It will have a dab of epoxy to keep the nut in place, although it probably isn't needed as there is no vibration and only occasional use as I mentioned above.

Evan
02-07-2010, 08:53 PM
I would not recommend stainless steel as an electrical contact. It will build up a nonconductive layer in time. Better is to use a tin plated rivet or screw. Tin oxide is a conductor

Jeffw5555
02-07-2010, 10:05 PM
This is replicating a system that has been in use for 25 years, and uses a stainless button since the beginning, and has never had an issue with non-conductance.