Bolt Torque Charts- needed
Bolt Torque Charts- needed
(OP)
I have been tasked to create a centeral database for all fastner types and their torque values. This table should be specific as to the material with the threads, if oil is used or not, etc. Any ideas where to collect this type of information on the web, via a downloadable chart?





RE: Bolt Torque Charts- needed
A good search engine and a few well placed words should get you what you need.
_______________________________________
Feeling frisky.........
www.tailofthedragon.com
RE: Bolt Torque Charts- needed
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Bolt Torque Charts- needed
There is a weak correlation between torque and pre-load, hence torque measurement is sometimes used as a method to control the amount of preload. Torque control may be adequeate when a joint can tolerate a wide variation in pre-load without unacceptable consequences.
RE: Bolt Torque Charts- needed
RE: Bolt Torque Charts- needed
RE: Bolt Torque Charts- needed
different loads,
different consequences,
i guess fatigue effects are more significant for airplanes than they are for refineries,
and i guess that the consequences of a failure (due to fatigue) are more significant at 30,000 ft ...
RE: Bolt Torque Charts- needed
the tension 2 times gives very good results
using the torque method, but what a pain.
Sometimes in the field, this is the only
method that is practical. I think that this
means that you would have to apply a greater
safety factor when using the torque method.
RE: Bolt Torque Charts- needed
RE: Bolt Torque Charts- needed
http://www.eng-tips.com/viewthread.cfm?qid=138994
http://www.eng-tips.com/viewthread.cfm?qid=133808
RE: Bolt Torque Charts- needed
You can easily create a bolt torque chart using Microsoft Excel, or some other spreadsheet. You need to research your bolts and materials.
Especially, you need to state all the assumptions you made in your calculations, just in case somebody makes a bunch of other assumptions.
When I made my torque chart, somebody printed it off, cut out the torque section and taped it to the wall of our assembly shop. Excluded from this printout were the fact that I was analyzing for 300 series stainless, 90% of yield, and lubrication from Loctite_242.
It pays to write out torque values on your drawings, torque chart or no torque chart.
The nice thing about the spreadsheet is that if somebody wants to use different materials and loading assumptions, they can copy your spreadsheet and hack with it.
JHG
RE: Bolt Torque Charts- needed
D = nominal bolt diameter. in; and P = bolt clamp load developed by tightening. lb.
2. Clamp load is also known as preload or initial load in tension on bolt. Clamp load (lb) is calculated by arbitrarily assuming usable bolt strength is
75% of bolt proof load(psi) times tensile stress area(sq in.) of threaded section of each bolt size.
Higher or lower values of clamp load can be used depending on the application requirements and the judgement of the designer.
3. Tensile strength (min psi) of all Grade 7 bolts is 133,000. Proof load is 105,000 psi.
4. Tensile strength (min psi) of all Grade 8 bolts is 150,000 psi. Proof load is 120,000 psi. Ref.:Fastening Reference, Machine Design, Nov 1977.
Captured from: Lamson & Session s Co. Chart
SAE Grade 8
Clamp Torque
Load lb.-ft. or lb.in.above dotted line
P (lb) Dry Lubricated
540 12 9 4-40
600 13 10 4-48
820 23 17 6-32
920 25 19 6-40
1260 41 31 8-32
1320 43 32 8-36
1580 60 45 10-24
1800 68 51 10-32
2860 144 108 1/4-20
3280 168 120 1/4-28
-------------------------------
4720 25 18 5/16-18
5220 25 20 5/16-24
7000 45 35 3/8-16
7900 50 35 3/8-24
9550 70 55 7/16-14
10700 80 60 7/16-20
12750 110 80 1/2-13
14400 120 90 1/2-20
16400 150 110 9/16-12
18250 170 130 9/16-18
20350 220 170 5/8-11
23000 240 180 5/8-18
30100 380 280 3/4-10
33600 420 320 3/4-16
41600 600 460 7/8-9
45800 660 500 7/8-14
54500 900 680 1-8
59700 1000 740 1-12
68700 1280 960 1-1/8 7
77000 1440 1080 1-1/8 12
87200 1820 1360 1-1/4 7
96600 2000 1500 1-1/4 12
104000 2380 1780 1-3/8 6
118400 2720 2040 1-3/812
126500 3160 2360 1-1/2 6
142200 3560 2660 1-1/2 12
RE: Bolt Torque Charts- needed
preload can vary by a third when using torque control ...
ie on a 1.5" bolt (his last line) a torque of 142,200 ft.lbs. is expected to produce a preload between 2400 to 4800 lbs (on dry threads, round numbers)
RE: Bolt Torque Charts- needed
All the more reason to fire up Excel and then read your Machinery's Handbook, or Bickford's Handbook if you have it.
I have a Stock Drive Products design handbook with screw torque charts, but all it lists is the material. It does not indicate what the author thought the maximum stresses were, or what the torque friction coefficient was, or why it was for that matter. You cannot trust these things until you do the calculations for yourself, and figure out how the author did them. It is not as if diamondjim's calculation is difficult.
JHG
RE: Bolt Torque Charts- needed
Thanks Again to all.
RE: Bolt Torque Charts- needed
Couple more observations:
Tightening by torque is generally regarded as accurate to about +/- 30%. Tightening by FEEL by an experienced mechanic is generally regarded as accurate to about +/- 35%.
Due to the larger o.d. and cone angle, a flat head screw will require significantly more torque to induce a given tension than a hex head or socket cap screw.
RE: Bolt Torque Charts- needed
ht
good luck
RE: Bolt Torque Charts- needed
FAQ559-1177
Hope you could share the files with the rest of us.
Thanks.
RE: Bolt Torque Charts- needed
Once I have added additional information to an Excel spreadsheet, I will share it through this thread if found useful. I will heed your advice about posting to a downloadable site instead of through email communication.
Thanks Again to all
RE: Bolt Torque Charts- needed