AISI 4140 HTSR

[mtipg]

Hi all;

I have a question. I am looking at an application where a 4 in shaft is being used to support an overhanging load that is barely spinning (less then 5 rpm). So a shaft with two bearings supporting a load that is to the right of BOTH bearings. I was given the shaft size and that the material to be used was 4140 HTSR. I have a couple questions.

A quick google search with HTSR -> H.T.S.R Hardened Tempered Stress Relieved

This leaves me at somewhat of a loss, What exactly does this mean. It seems a little vague. Is this a designation that can give me a yield point so that I can run some FEA simulations or no?

when I look up 4140 in my machinery handbook I get a wide range of yield points depending on the tempering temperature.

Not sure what to go with as 4140 ranges from:

AISI 4140 Annealed (1500F) - 60,500 psi
(ref. page 467 Machinery Handbook 27th edition)

AISI 4140 Tempered @ 400F - 238,000 psi
(ref. page 469 Machinery Handbook 27th Edition)

a pretty big range to work with...

Any indight into this material would be a huge help.

 

[mtipg]

To better sum up my question:

Does 4140 HTSR, have any tangible material specs? I need yield strength for FEA analysis. If there are specifications what are they/where can I find them? If not, I will need to find more information.

 

[redpicker]

With nothing more than 4140 HTSR, you don't really have anything to go with. Generically, however, I have seen this to imply B7 (ASTM A193 Gr B7). In fact, I've been chastised for suggesting that it could possibly mean anything else. (For a 4" bolt, B7 material would have a minimum yield of 95,000 PSI)

Castigation or not, I would not make such an assumption. If I had to do the analysis with only this information, I would state the analysis was based on B7 material with a yeild of 95,000 PSI.

rp

 

[mtipg]

Thanks!

I preformed the analysis and found the max stress to be about 57,000 psi, so I stated that number and then stated what I figured the yield was for that kind of material. Then told him he needs to check that number with his steel supplier because they know the values where mine is only an educated guess. With 57,000 psi being well below any of the possible yields I have come up with and no real impact loads on the system, I feel it will be a safe bet. Thanks for your help.

 

[unclesyd]

I thought I posted this yesterday, it appears that my senior moments are getting longer.

Several acquaintances in the machine shop business have been moving away from commercial grades of AISI 4140 due to some quality problems.

The have been gravitating to the so called proprietary steels listed below even tough they carry a small premium to merchant grade 4140. If you stick with 4140 I would advise using either what is referred to as Aircraft quality or one of the proprietary steels below.
We switched from using AISI 4140 in our shop a number of years ago. We used a lot of Miralloy aside from the material point of view but there accommodations by their representative.

Sheffield #20

http://www.northamerican-steel.com/highstrength-highstrength.html

Flexor

http://www.pennsylvaniasteel.com/flexor.php

Miralloy

http://www.associatedsteel.com/products-alloys-miralloy.shtml