Best screw material?

[macardoso]

If you can, leave some extra length of stock and get a center on the screw. Will make threading easier. Just cut the excess off when you're done.

Expect to screw up a few while you learn to single point. It isn't hard but there are a lot of steps which must be done correctly or your thread won't come out right.

 

[rgray]

I know there are easier ways to do this but: I own a lathe! (I haven't gotten over saying that yet) I work in a hardware store so I have the screws (and dies) to do it the easy way but I don't like the way they would come out. I also want to practice screw making, so yea, I'm going to do this the hard way.

The screws in the store are roll threaded. 12L14 might be a little weak for a screw, also not known to be heat treatable, but would be good practice material. As would aluminum.
I would second the 1144 stressproof as material. Machines easily.
I would suggest brass. A custom screw from brass or bronze would be worth making. Not sure if that meets your strength requirement for it's use.

 

[extropic]

Really? You mean to case harden it?
I know it's great to machine but the carbon content is something like .14% as I recall??

I think 12l14 is not a good steel for hardening, though I have not tried it.

Maybe I should have been more specific.
I was thinking of carburizing (case hardening), which is considered a heat-treatment.
On second thought, case hardening a 12L14 8-32 screw might be very difficult to achieve without leaving the threaded portion too hard (brittle).
I'll edit my earlier post (if I can).

 

[walterwoj]

Hardness shouldn't be a factor and torque shouldn't either. These are thumb screws for locking the dials on the cross-feed and top-feed screws to '0'. Very minimal torque needed for that. I've been reading all your posts and researching them. I think I'm going to order some 12L14 and 4140 (or 4130) since they are both relatively common and cheap while still being machinable. Any recommendations for online suppliers? Any that support the forum?

PS - I was thinking about the fact these are really small. The idea of using a center sound wise and I might make the threaded sections and then make a knurled cap and press them together so I can eliminate the gutter. Maybe, we'll see how it turns out. I'll definitely post pics when I do it...

 

[mikey]

For your application, a low stress/low torque one, 12L14 will work fine but it tends to rust easily so keep it oiled. A better choice is 1144 stressproof. It machines nicely, is semi-hard and resists rust fairly well (although you should oil it).

If it was me, I would make it from Brass.

 

[Chewy]

Top left is a fire starter that screw into bottom left side. Top right is a glass breaker point for escaping cars. The clip on the top right serves as the metal for the fire starter to strike and serves as half a-- srew driver. And the bottom part also serves as a ball point pen.View attachment 309879

OOPS!! Posted to wrong Thread!

 

[BtoVin83]

When you wanted to single point a 8-32 I really didn't think it would be easy but here it is, I wouldn't want to do that for a living though.

 

[JimDawson]

I guess I would start with a grade 5 or grade 8 bolt. then just turn to size. I use bolts all the time for stock material.

 

[savarin]

So I had to translate 8/32 from the medieval size back to metric M4-0.7 to get an idea of size.
Anything wrong with using stainless?
I have made quite a lot of 4mm knurled screws in stainless with no problems.
I will start single point till almost done to ensure everything is centred then do a final touch up with the die.
I usually start most threads in stainless by single pointing as its a bit tough sometimes to cut from scratch with a die.
Finish with the die in the standard way then sometimes reverse the die and cut right up to the shoulder.
Extend the rod then cut the knurls and part.
I think the stainless knurled screws look really good and at the size you are cutting then straight knurls look even better.

 

[extropic]

snip I think I'm going to order some 12L14 and 4140 (or 4130) since they are both relatively common and cheap while still being machinable. Any recommendations for online suppliers? snip

Take a look at McMaster-Carr. They are not always the absolute lowest price, but they have what you want, S&H is always reasonable, ordering is easy and delivery is quick.