Questions tagged [threads]

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Compute compressive forces necessary for thread rolling

Is there a mathematical method or reference source/handbook for computing the compressive forces necessary for thread rolling? I realize I could use FEM, but that is a lot of work, so I am hoping to ...
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1 vote
1 answer
574 views

How to find the minimum shear area of a rectangular thread

I am trying to find a method of calculating the minimum shear area of the following rectangular thread form. It is a 4.125" square thread, 8 T.P.I., straight, right-hand thread. The thread is loaded ...
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2 votes
0 answers
66 views

What is the load response of a threaded fastener?

Due to the fact that pipe flanges rely on bolts, and bolts rely on friction, it seems obvious to me that in deflecting to meet the load, the nut will immeasurably turn. So my question is - how much? ...
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3 votes
3 answers
660 views

Measuring pipe bolt torque without a torque wrench

I've had trouble with leaky pipe flanges, since my flanges are made of plastic. The problem comes down to the fact that sealing a flange is based on torque. Torque relies on bolt friction, which can ...
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1 vote
1 answer
317 views

Flat Head Machine Screws with Undersized Threads

I am in search of a flat head machine screws with an 82 degree countersink that have 1/4-20 UNC thread, but have a countersunk head that is characteristic of a 5/16-18 standard screw. That is, I want ...
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2 votes
0 answers
175 views

Thread-locking on AISC Clevises

I have a project that includes some standard AISC clevises on threaded rods in pure tension. I am trying to find guidance on how best to address the possibility that the rod could rotate with respect ...
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  • 4,501
4 votes
1 answer
248 views

British tapered pipe thread; Wall thickness? & Thread designation tpd?

I have to draw two custom pipes, 1 1/4" & 2", with on one end male tapered pipe thread and on the other end parallel pipe thread. The connections are Parallel female thread with a tapered male ...
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10 votes
2 answers
483 views

Are threads machined from high tensile steel more susceptible to damage?

I have an ASTM A311-04 1.25" diameter round 1050 steel bar that exhibits a tensile strength reading of 155,227 PSI. Normally, we receive material in the 13-133,000 PSI range. The bar is machined to a ...
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8 votes
1 answer
3k views

Can nuts safely be removed from bolts where the threads have been intentionally damaged?

On old bridge plans I have occasionally seen a note to "burr threads after installation". This was done to keep the nuts of bolted connection from loosening all the way and falling off of the bolt. ...
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12 votes
5 answers
12k views

Why are most standard bolt threads single start?

When looking at thread descriptions, one of the basic properties is always the number of thread starts. As far as I could tell, all of the major standard bolt threads are single-start. This includes: ...
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6 votes
1 answer
3k views

Is the tolerance of pitch of a thread standarized?

As I was browsing ISO 965-1 it defines tolerances on a plenty of variables regarding metric threads, but it gives the pitch of the thread as a simple number from an allowed set ( 3 – 2 – 1,5 – 1– 0,75 ...
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5 votes
2 answers
154 views

How to let a "screw" leave and reenter a thread

The setup Consider a cylinder inside another cylinder (placed with their symmetry axis horizontal). The inner cylinder is about Ø100 mm in diameter and a centimeter or two in lenght/thickness. On ...
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  • 163
5 votes
2 answers
7k views

What does "28" and "27" mean on my metric thread pitch gauge?

I have a metric thread pitch gauge that came in a tap and die set, it has pitches like $0.75$, $0.8$, $1.25$, etc. which is the distance between each thread. However there are two gauges that say $27$ ...
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