Large Scale Central

Dies and rod blanks

Modeling
#1

Big brain fart here…:slight_smile: :slight_smile:
I used to know this stuff, back when I didn’t have “Mad Cow.”

What is the rod diameter needed for 2:56 and 4:40 thread?
I want to make my own tension bars for a few projects I have. I used 2:56 ready rod on one bridge, and I don’t like the looks of a fully threaded rod. I’d like to replace it with blank rod.
Thanks,
jb

#2

John:

For threading rod:

2-56 requires 0.086" diameter rod

4-40 requires 0.112" diameter rod

I personally use quite a bit of 3-48 for bridge and other hanger rods:

3-48 requires 0.092" (3/32") diameter rod which is readily available. It equals ~1.9" diameter in 1:20 scale.

Here is a thread / size chart from Micro-Mark in .pdf format:

TAPS & DIES CHART

It also shows their available stocked rod sizes at the bottom.

Happy RRing,

Jerry

#3

Jerry,

That’s a great source! I just added it to the Articles. Thought it was worth keeping in an easy reference location. Thanks for the source.

#4

Jerry,
Thank you very much!
I guess I’ll order some brass rod!
I don’t have a 3-48 die, but I like the idea of a bigger than 2 and smaller than 4.

jb

#5

Pardon my ignorance but what do those numbers represent?

#6
Ray Dunakin said:
Pardon my ignorance but what do those numbers represent?
The first number refers to the rod size, the second to the number of turns per inch. That is if I remember correctly!?!

PS just to be sure I got out the Machinist’s Handbook; anything that is smaller than 1/4" (Basic major diameter i.e.OD) is designated with a number, starts at 12 and goes down to 0. The common sizes are 10; 8; 6; 5; 4; 2; 0. All sizes in UNC and UNF, except 0 which only comes in UNF (the metric equivalent would be M1.5 x 0.3175).

#7
Ray Dunakin said:
Pardon my ignorance but what do those numbers represent?
Ray:

Han’s reply is correct, but also take a look at the linked Micro-Mark page. It more fully explains the ANSI ‘small thread’ specification system.

John:

K&S usually has 36" lengths of 3/32" diameter brass rod on their commercial display racks. I get it at an Ace Hardware store in our nearest ‘town’. Better utilization than the 12" pieces and saves trying to order and get it shipped. Unfortunately they didn’t have the dies, so I ordered a couple from McMaster-Carr.

Happy RRing,

Jerry

#8

Jerry, that’s wonderful - any chance of posting a metric version?

#9
Ric Golding said:
Jerry,

That’s a great source! I just added it to the Articles. Thought it was worth keeping in an easy reference location. Thanks for the source.


Thanks for adding it. I really like that they explain the ANSI numbering system for the ‘small thread’ series. The nominal rod and hole dimensions they give will produce usable threads for our purposes without worrying about thread percentage, class, etc.

Happy RRing,

Jerry

#10
Dave Healy said:
Jerry, that's wonderful - any chance of posting a metric version?
Dave:

Sorry, but I haven’t seen a simple one like that for metric threaded rods. There are lots of on-line tap drill size charts for both ANSI (inch) and ISO (metric) threads, but I haven’t seen one for ISO die and rod sizes.

I use my printed references (like Machinery’s Handbook) when I need metric, but even they don’t cover all the smaller metric sizes.

Happy RRing,

Jerry

#11

Jerry,
I posted it out of my own selfishness. I can not tell you how many times I’ve wanted that info and have it in a file or somewhere and it becomes a rediscovery of the obvious every time. The “Articles” section of LSC has become a portable file cabinet on and offline at my home and while on the road. Its great to have things available if there is is internet access and also constantly backed up without me having to think about maintaining it.

Another service Bob provides with little fanfare.

#12

Don’t forget the reference section, either.

#13

Metric chart? I could supply that, just as soon as I get a-round to it. :wink:

At the moment I’m working on signals.