How to work out the tensile strength in pounds

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Discussion Overview

The discussion revolves around calculating the tensile strength of a drilling pipe based on its yield strength provided in a raw material certificate. Participants explore the necessary data and calculations required to determine the maximum weight the pipe can withstand, including unit conversions and cross-sectional area considerations.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant inquires about the maximum weight a drilling pipe can withstand based on its yield strength of 863 N/mm².
  • Another participant notes that the question is complicated and requires exact details to be solvable.
  • There is a suggestion that the maximum tensile strength could be looked up in a table or obtained from the supplier, depending on the material.
  • Participants discuss the importance of converting units, with one stating that 863 N converts to 194 lbf and provides a conversion for mm² to in², resulting in a tensile strength of 125,161 lb/in².
  • One participant calculates the tensile load based on the cross-sectional area of the pipe and emphasizes the need to consider the load rating from the supplier and safety factors.
  • Another participant recalculates the cross-sectional area of the pipe and provides a different tensile load limit, prompting a correction from the original poster regarding their calculations.

Areas of Agreement / Disagreement

Participants express differing views on the calculations, particularly regarding the cross-sectional area of the pipe and the resulting tensile load limits. There is no consensus on the correct area or load limit, as calculations vary among participants.

Contextual Notes

There are unresolved issues regarding the assumptions made in the calculations, particularly concerning the cross-sectional area and the application of safety factors. The discussion also highlights potential discrepancies in unit conversions.

Rustam
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Hi to all.
I have a raw material certificate of drilling pipe - there is a YS=863 N/mm2. I would like to know what is the maximum weight in pounds this pipe can withstand.
 
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Welcome to PF! This is a complicated question that requires exact details in order to be solvable.
 
russ_watters said:
Welcome to PF! This is a complicated question that requires exact details in order to be solvable.
Thank you, Russ.
What data is required for that?I didnt expect the thing was so complicated...
 
Sorry, I may be missing something due to a possible mismatch between the title and post/confusing terminology("weight it can withstand" and "pipe" had me envisioning a structure). If it is just the max tensile strength, you can probably look it up in a table based on the material name. Or ask the supplier.
 
Part of this is a units conversion issue. 863 N = 194 lbf and 1 mm ^2 = 0.00155 in ^2, i.e, the result is 125,161 lb/in^2. What is then required is the x-sectional area of the drill pipe.

At the same time, this does mean that the drill pipe's rated tensile load is equal to that result, so you must request the load rating from the drill pipe supplier to insure that the drill pipe thread joint rating is equal to or greater than that of the above calculated load bearing value plus the fact that there is surely a safety factor that is applied to the actual maximum yield stress and the thread failure load values.
 
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JBA said:
Part of this is a units conversion issue. 863 N = 194 lbf and 1 mm ^2 = 0.00155 in ^2, i.e, the result is 125,161 lb/in^2. What is then required is the x-sectional area of the drill pipe.

At the same time, this does mean that the drill pipe's rated tensile load is equal to that result, so you must request the load rating from the drill pipe supplier to insure that the drill pipe thread joint rating is equal to or greater than that of the above calculated load bearing value plus the fact that there is surely a safety factor that is applied to the actual maximum yield stress and the thread failure load values.
Thank you very much, JBA.
I got almost the same result (slight conversion issue). The OD of pipe is 5.5" and ID is 4". The pipe itself is integral (no welds etc.). So, the rating of pipe body is equal to that of tool joint. I calculated 1784100 lbs (converted the 863 N/mm2 to 125200 psi (lbs/in2) and then multiplied the cross-sectional area of pipe (5.5"-4"=14.25 in2) with 125200).
I just would like to check if my calcs are right.
 
You need to recalculate your x-sectional area for the pipe using the given 5.5 and 4 in dia values. My result for the area is 11.1919 in^2 for a total load limit of 1,401,229 lbs using your 125,200 psi value.
 
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JBA said:
You need to recalculate your x-sectional area for the pipe using the given 5.5 and 4 in dia values. My result for the area is 11.1919 in^2 for a total load limit of 1,401,229 lbs using your 125,200 psi value.
Yes, JBA, I didnt apply a conversion...my bad.
I agree with you.
Thanks again for an interesting discussion and help.
 

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