What is wrong with 3-48 ?

[Hilmar]

I noticed lately that in most flyers the Taps for threading jump from 2-56 to 4-40. Seldom I see the 3-48's unless you go to the main catalogs. Does that mean the 3-48 is on the way out??
Also where will one get the Model type hardware, like Nuts and Bolts in above sizes. Coles seems like a bade choice, I give up on them.
Hilmar

 

[kcmillin]

I get my small screws from Enco. They are sold in packs of a hundred for $5-$10. Watch out though, the five to ten dollar packs are of the more common sizes (lengths not thread size), , if you choose something funny like 7/32" length under the head the price can tripple. So stick to the eights and sixteenths in some cases, and you should get a deal.

Kel

 

[Tin Falcon]

for whatever reason (probably) attempt to standardizes and keep inventory down )most places focus on the even numbers. while us model folks and gunsmiths still use the odd sizes like 3-48 and 5-40 they are not real common.
tin

 

[Hilmar]

Hi Kel,


I was thinking off the model hex Head Screws, By ENCO they don't come that small.
Hilmar

 

[Tin Falcon]

http://www.microfasteners.com/catalog/products/MSCHBB.cfm
3-48 hex head brass. $8.00 a hundred.
they also carry 3-48 taps and dies.
Tin

 

[Lew Hartswick]

I remember that BNC connectors used one of the #3 screw size don't quite remember
if it was 3-48 or 3-56. this was the square mounting flange ones. Use to mount a
bunch of them.
...lew...

 

[Catminer]

Hilmar;

American model engineering supply for scale hardware
http://www.americanmodeleng.com/index.html

Peter

 

[cfellows]

I always wondered why 3-48 and 5-40 aren't the accepted standards since they represent 3/32" and 1/8" respectively.

Chuck

 

[maverick]

Chuck, I don't have the straight scoop, but I'd say that Tin is right. It's a cost saving measure.

Peter- Thanks for the link. It's a keeper. I have a small CNC lathe that I make customers parts and
occasional runs of my own parts but for the price of 5 or 10 screws I'd just as soon not set it up.

Mike

 

[Mainer]

Yes, it's to reduce inventory. There also used to be number sizes 7, 9, 11, and others all the way up to 16 or 20, I think, but those became obsolete a long time ago; even my 6th edition of Machinery's Handbook mentions them only in passing.

 

[kvom]

I use 5-40 a lot as it's 1/8" stock. There's no problem in getting these screws from Enco or other sources. I've never used 3-48 myself.

 

[bearcar1]

I have never purchased the small fasteners from Enco but I have from American Model Engineering and I have to say that the quality of finish and thread are excellent. I used to buy the fasteners from one of the sources mentioned above and they would a lot of times have sharp pips remaining on the heads and some of the threads would not be crisp and fully formed, like the die was dull or the major diameter was too small. Whatever the reason, it resulted in me being a lost customer. AME has since gotten all of my business as they have proven time and time again they can deliver consistent quality. And they are nice folks to speak with as well.

Jim B.

 

[mu38&Bg#]

M2.5 is virtually the same size as 3-48 if the size is critical. Of course, I like metric.

 

[kvom]

I've bought screws and nuts from AME where I wanted scale dimensions on the hex heads. In fact, I just ordered some today.

For socket head screws Enco's are just fine, and inexpensive.

 

[cfellows]

I needed a couple of m4.0 x 0.7 x 40mm SHCS for the cross slide extension I made for my mini lathe and, being impatient, I went to Lowes to see what I could find (silly me).

They had a very small selection of m4.0 x 0.7 with the maximum length being about 12mm. OK, I thought, I'll rethread it to 8-32, but, they only stocked those up to about 1".

I continued to browse and found a whole drawer full of hex head metric bolts, with m4.0 x 0.7 all the way up to 50mm. I can only assume these kinds of bolts would be stocked as replacements for imported weed eaters, lawn mowers, etc.

So, I wound up buying a couple of the hex head bolts, turning the heads down to the diameter of SHCS heads and cutting a slot in the top so I could use a screwdriver to install and tighten them.

 

[Tin Falcon]

FYI related sort of I decided to buy a new wire stripper ,crimper, screw cutting pliers. I wanted quality here IMHO this is one place where cheap imports do dot cut it. Pun fully intended. I ended up with channel lock brand. But while comparing noticed that the Klein brand a few buck more include the 5-40 size in the screw cutting section. so if you use 5-40s the Klein brand may be the way to go.
Tin