• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You

  • As some of you know, I have wanted to stop managing H-M for some time. It's a tremendous strain on my personal life. I want to set up my own shop. In September, September 15, to be exact, it will be 8 years that Hobby-Machinist has been in existence.

    We've seen a lot of changes. In March, 4 moderators left to start their own site. They took some of you with them. So now you have split loyalties. You know who you are. They didn't like my way of managing this place, and thought they could do better without me. They didn't. The only thing holding them together is that they hate me. Their site was down until mid July. That is why I wanted to stay involved on here until they could learn to run this place. But they wanted me to leave right away, without the training part.

    Anyway, I have been training VTCNC to run things here. Dabbler is going to learn too. I feel that they are ready to start taking over the operation. I will be here to help in case they need, but I don't think they will. Tony Wells is and will be here also to consult with. I will be doing backups, upgrades, and installing addons. Other than that, I don't want to know about this place.

    What about the 4 moderators who were disloyal? I don't care. It isn't my call anymore. I would think that, rather than fumble, they ought to come back and do good work. That's up to them. If they want to return to try to lead more members to their site, I am done caring. I suffered too much aggravation worrying about it. I don't plan to spend any more. What they do impacts on them. I have my own opinions including those of you who followed them there. No longer my problem.

    I am leaving this place in good operating condition, and financial condition.
    --Nelson
[4]

The correct stock size for threading 3/8-16 stud

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

stioc

Registered
Registered
Joined
Feb 22, 2017
Messages
172
Likes
356
#1
The machinery handbook says .375 for major diameter. I started with a .382 stud but by the time I got some depth to the threads the major diameter changed to .355 - needless to say the nut threads on very loose. So should I've started with say a .4" stud?
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,123
Likes
1,559
#2
No, start with .375" diameter and don't cut the threads undersize, as you apparently did; having said that there is nothing really wrong with having the stock a bit undersize, especially for coarse thread pitches. When I single point thread, by the time I am on size with the threads, I generally have to file off the crests of the threads to eliminate burrs, resulting in a undersize major diameter; little thread strength is lost by the insignificant reduction in diameter.
 

stioc

Registered
Registered
Joined
Feb 22, 2017
Messages
172
Likes
356
#3
Thanks! I figured out my stupid mistake. The nut I was using to test the threading is an M10 not 3/8" :eek 2: Threw me for a loop and I was so proud of myself that I got all the angles and things right, the pitch was correct without looking any of that stuff up.
.
 

GoceKU

Registered
Registered
Joined
Jul 14, 2017
Messages
564
Likes
955
#7
We have all done it, some metric and inch sizes are so close is hard to tell them apart especially on french and italian machines and automobiles, they use both system on the same part. Hair pull stuff.
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,123
Likes
1,559
#8
I recently had to repair a 2 1/2" steam valve, where the bonnet had broken; the bonnet was held on the body with 1/2-12 studs and nuts, the packing gland was fitted with 1/2-13 studs and nuts; I had tried a 1/2-13 not on the gland studs and assumed that it was all 1/2-13 ----WRONG!
After my discovery, I had to re make my parts to repair the valve, perhaps a half hour's work; "Could be worse, could be raining".
To see where this valve goes, Google "Sturgeon's Mill", and look at our web site.
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,254
Likes
5,612
#9
the packing gland was fitted with 1/2-13 studs and nuts; I had tried a 1/2-13 not on the gland studs and assumed that it was all 1/2-13 ----WRONG!
Joseph Whitworth strikes again! Well, not really. Whitworth was first to have accepted standards for fasteners... Still 1/2-12 threads are most
often Whitworth threads. Ask me how I know!

(British cars...)
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,123
Likes
1,559
#10
1/2-12 was our standard before World War 1, unless you were dealing with Brown & Sharpe, their standard was 1/2-14
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,254
Likes
5,612
#11
1/2-12 was our standard before World War 1, unless you were dealing with Brown & Sharpe, their standard was 1/2-14
Thanks for that, John. I was not aware of it...
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,123
Likes
1,559
#12
If we are talking odd ball threads, here is another one: I have a set of taps and dies that are nominally sized, but plus 1/32", like 5/8-11+1/32; they were used for threading pump rods and couplings when the old pumps were used that had the cylinder at the bottom of the well and the rod operated it from mechanism above ground, be it a windmill or power driven pump jack.
 

silence dogood

Active User
H-M Supporter - Gold Member ($25)
Joined
Jul 10, 2013
Messages
367
Likes
219
#13
A 100 million + mars space went kapoot a few years ago because NASA forgot to covert from english to metric. :oops2:
 

P. Waller

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Mar 10, 2018
Messages
328
Likes
195
#14
One may purchase oversized and undersized taps for holes in parts that will later be plated or hardened.
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,123
Likes
1,559
#15
Yes, I had a set of them (oversize taps) at my shop, they were marked (+5), that is, .005 oversize. Some of our readers may not know that steel swells when hardened. Plating only effects the mouth of the tapped hole, at least in the case of relatively small holes due to the lack of circulation of the electrolyte through the hole, and I think a cathode is required in a hole plus circulation for effective plating in holes.
 
[6]
[5] [7]
Top