Not Another Metric Thread

[boatgeek]

I read someplace that shear strength for a bolt might be 40 percent of tensile.

If you do up your Mohr's Circle (shudder), shear yield is nearly exactly 0.6 * tension yield. Close enough as not to make a difference anyway.

 

[lr64]

Again, kramer714 did not say to stand under the Hyundai. I doubt the manufacturers of "2 Ton" epoxy want you to stand under their test weight, either. Allowables are another story. The 125kpsi was for AN bolts, meant for aircraft. I don't know if the AN spec includes 1/4-20 or #8

 

[SolarYellow]

AN spec goes down to 10-32:

https://jet-tek.com/wp-content/uploads/2017/04/an3_thru_an20_specs.pdf

 

[kramer714]

AN spec goes down to 10-32:

https://jet-tek.com/wp-content/uploads/2017/04/an3_thru_an20_specs.pdf

Again, kramer714 did not say to stand under the Hyundai. I doubt the manufacturers of "2 Ton" epoxy want you to stand under their test weight, either. Allowables are another story. The 125kpsi was for AN bolts, meant for aircraft. I don't know if the AN spec includes 1/4-20 or #8

Again, kramer714 did not say to stand under the Hyundai. I doubt the manufacturers of "2 Ton" epoxy want you to stand under their test weight, either. Allowables are another story. The 125kpsi was for AN bolts, meant for aircraft. I don't know if the AN spec includes 1/4-20 or #8

Wow, didnt think the whole bolt allowable thing would be in play,

Ok so, suspended Hyundai (circa 1986) Analysis (I really need a different hobby...)

The kid wanted to use a bolt originally, bolt not screw. Side note, had an engineer ask whats the difference between a bolt and a screw? I gave him the simple answer, 'bolts are for bolting, screws are for... well you know the rest' .

1) For bolts you don't use the threads for shear, that is really bad form, like as bad as putting catsup on a hot dog bad... lets start with that.

2) Lets ignore fatigue, corrosion, bolt fit-up, tolerances and all those important things... for now.

3) And for shear, double shear is the best way of loading a bolt. Pure shear, like the kind you get from prefect reamed holes in a clevis My story - i get to remember the details any way I want.

4) Allowable load (see note 2) ok so if you want to know about bolts, go to the US Bolt Counsel RESEARCH COUNCIL ON STRUCTURAL CONNECTIONS www.boltcouncil.org www.boltcouncil.org Again, keeping with a theme, be careful if you google screw council at work. And since you guys shamed me into this, ASTM A490 (side note if you go visit the Bolt Council, stop by Portillo's for a dog and an Italian beef, 5 minute walk up on Ontario Street, se note 1 re: catsup)

5) Hyundai Excel 1986 curb weight was 973kg (less than a metric ton if we want to mess with units), or is that 153 stones?.. lets just call it 2,143 lbs, add the 8 track and fuzzy dice and we will call it 2,150.

6) 'Couple of Hyundais' would equal (2) for a total load of 4,300 lbs or keeping the units straight 2 Hyundais, If you want to convert (2) 1986 Hyundais are = to (1) Tesla (model Y)

7) Shear Load, we are talking perfect double shear, The mythical perfect shear, perfectly line bored / reamed holes. load with a universal joint, and just snug on the nut. So each side of the joint will need to hold 1/2 of the total load or ( 1/2*Couple of Hyundai) = (1) Hyundai = 2,150 lbs.

8) Allowable load A490 bolt 75KSI PURE SHEAR - NO ENVIRONMENTAL FACTORS / NO FIT FACTORS / NO TENSION (see table 5.1 from Bolt Info )

9) Dumb Simple SINGLE Shear - Rn = Fn Ab where;

• Rn = nominal strength (shear strength per shear plane or tensile strength) of a bolt
• F n = nominal strength per unit area from Table 5.1 for the appropriate applied load conditions, ksi, adjusted for the presence of fillers as fillers as required Perfect shear - no fillers! For PURE SHEAR 75ksi
• Ab = cross-sectional area based upon the nominal diameter of bolt, in.2 - For a 1/4 inch bolt that is .0491 square inches.

10) so, a 1/4 inch really good bolt in a ideal loading condition, with perfectly made parts, load once... can suspend....

• Rn in Hyundai =,((75,000 psi) * .0491in2)* (1 Hyundai / 2,150 lbs)
• Rn = 1.71 Hyundai
• Or in double shear, (3.42) Hyundai > than a couple

To all you kids out there, dont try this at home....

 

[jd2cylman]

So is this now a glue thread???

 

[SolarYellow]

So is this now a glue thread???

No, it's a bolt thread. Or if you want to say that other thing...

 

[lr64]

So is this now a glue thread???

No, that would require at least a square inch. ;-p

--------
The numbers are in the ballpark. Or, if it's a really small ballpark, suitable only for stickball:
-A 1986 Hyundai would probably be in a junkyard, with some parts removed. Maybe even the engine.
-We didn't say WHERE they would be suspended. How about underwater or on Mars? We could switch to one Tesla and have Elon suspend it for us. Isn't there one out in that neighborhood already?
--------

At home would be fine as long as no one stands underneath. Anyone with a big tree and a come-along......

 

[Art Upton]

I found a missing 14mm wrench

 

[kramer714]

Remember, this analysis was performed by a trained professional on a closed course. I even found the old College class description..

ME 321 Advanced Automotive Engineering: Single-Bolt Automotive Suspension Systems

This upper-level course delves into the advanced engineering principles required to suspend an entire Hyundai vehicle using a single bolt. Students will explore the mechanical properties, stress analysis, sarcasm and design considerations essential for achieving vehicle suspension, safety, and performance with such a unique single bolt system. Through a combination of theoretical lessons and hands-on projects, beer drinking, and review of Road Runner cartoons, the course will cover material selection, the dynamic response of a Hyundai while hanging, suspension components under extreme loading conditions, and the innovative engineering solutions needed to manage these stresses. By the end of the course, students will be equipped with the knowledge and skills to design, analyze, and implement the lifting and support of a multitude of vintage Hyundai with a single bolt, preparing them for advanced roles in automotive engineering, wasting time on online forums, and attempted road runner capture.

 

[NTP2]

Remember, this analysis was performed by a trained professional on a closed course. I even found the old College class description..

ME 321 Advanced Automotive Engineering: Single-Bolt Automotive Suspension Systems

This upper-level course delves into the advanced engineering principles required to suspend an entire Hyundai vehicle using a single bolt. Students will explore the mechanical properties, stress analysis, sarcasm and design considerations essential for achieving vehicle suspension, safety, and performance with such a unique single bolt system. Through a combination of theoretical lessons and hands-on projects, beer drinking, and review of Road Runner cartoons, the course will cover material selection, the dynamic response of a Hyundai while hanging, suspension components under extreme loading conditions, and the innovative engineering solutions needed to manage these stresses. By the end of the course, students will be equipped with the knowledge and skills to design, analyze, and implement the lifting and support of a multitude of vintage Hyundai with a single bolt, preparing them for advanced roles in automotive engineering, wasting time on online forums, and attempted road runner capture.

I’ll try and sneak that into a actual class and see if anyone knows..

 

[lr64]

ME 321 turned out to be a real whopper, and a waste of time. Look it up if you don't believe me. ;-p

 

[boatgeek]

ME 321 Advanced Automotive Engineering: Single-Bolt Automotive Suspension Systems

Your university must have been a little weird. At most places, this kind of specialty class would be a 400-level technical elective, probably a senior professor's pet project that they can't take away because of departmental politics.

ME 321 turned out to be a real whopper, and a waste of time. Look it up if you don't believe me. ;-p

See, that's why it should be a 400-level class. Nobody expects everyone to suffer through that stuff, even to please a senior professor's ego.

 

[kramer714]

1988 Hyundai Excel 2-Door Hatchback For Sale​

https://buysellsearch.com/view/vehicles/cars/129534374/r/vehicles/cars/mk-hyundai/ml-excel

1988 Hyundai Excel 2-Door Hatchback 1.5L I4. 4 Speed Manual. Car is in good shape, has been sitting for several years. Not sure if it runs anymore since it has been sitting. Cleaning up yard. $250. If it does not sell it will be crushed.

In case you want to check my math....

 

[lr64]

Your university must have been a little weird. At most places, this kind of specialty class would be a 400-level technical elective, probably a senior professor's pet project that they can't take away because of departmental politics.

See, that's why it should be a 400-level class. Nobody expects everyone to suffer through that stuff, even to please a senior professor's ego.

You didn't actually look up "Me-321", I suspect. You will find that it was indeed both a whopper and a waste of time.

https://en.wikipedia.org/wiki/Messerschmitt_Me_321_Gigant

 

[bjphoenix]

Wow, didnt think the whole bolt allowable thing would be in play,

Ok so, suspended Hyundai (circa 1986) Analysis (I really need a different hobby...)

The kid wanted to use a bolt originally, bolt not screw. Side note, had an engineer ask whats the difference between a bolt and a screw? I gave him the simple answer, 'bolts are for bolting, screws are for... well you know the rest' .

1) For bolts you don't use the threads for shear, that is really bad form, like as bad as putting catsup on a hot dog bad... lets start with that.

2) Lets ignore fatigue, corrosion, bolt fit-up, tolerances and all those important things... for now.

3) And for shear, double shear is the best way of loading a bolt. Pure shear, like the kind you get from prefect reamed holes in a clevis My story - i get to remember the details any way I want.

4) Allowable load (see note 2) ok so if you want to know about bolts, go to the US Bolt Counsel RESEARCH COUNCIL ON STRUCTURAL CONNECTIONS www.boltcouncil.org www.boltcouncil.org Again, keeping with a theme, be careful if you google screw council at work. And since you guys shamed me into this, ASTM A490 (side note if you go visit the Bolt Council, stop by Portillo's for a dog and an Italian beef, 5 minute walk up on Ontario Street, se note 1 re: catsup)

5) Hyundai Excel 1986 curb weight was 973kg (less than a metric ton if we want to mess with units), or is that 153 stones?.. lets just call it 2,143 lbs, add the 8 track and fuzzy dice and we will call it 2,150.

6) 'Couple of Hyundais' would equal (2) for a total load of 4,300 lbs or keeping the units straight 2 Hyundais, If you want to convert (2) 1986 Hyundais are = to (1) Tesla (model Y)

7) Shear Load, we are talking perfect double shear, The mythical perfect shear, perfectly line bored / reamed holes. load with a universal joint, and just snug on the nut. So each side of the joint will need to hold 1/2 of the total load or ( 1/2*Couple of Hyundai) = (1) Hyundai = 2,150 lbs.

8) Allowable load A490 bolt 75KSI PURE SHEAR - NO ENVIRONMENTAL FACTORS / NO FIT FACTORS / NO TENSION (see table 5.1 from Bolt Info )

9) Dumb Simple SINGLE Shear - Rn = Fn Ab where;

• Rn = nominal strength (shear strength per shear plane or tensile strength) of a bolt
• F n = nominal strength per unit area from Table 5.1 for the appropriate applied load conditions, ksi, adjusted for the presence of fillers as fillers as required Perfect shear - no fillers! For PURE SHEAR 75ksi
• Ab = cross-sectional area based upon the nominal diameter of bolt, in.2 - For a 1/4 inch bolt that is .0491 square inches.

10) so, a 1/4 inch really good bolt in a ideal loading condition, with perfectly made parts, load once... can suspend....

• Rn in Hyundai =,((75,000 psi) * .0491in2)* (1 Hyundai / 2,150 lbs)
• Rn = 1.71 Hyundai
• Or in double shear, (3.42) Hyundai > than a couple

To all you kids out there, dont try this at home....

Well the original discussion was for 125ksi bolts, A490 is 150ksi. A325 is 125ksi, or maybe 120ksi, roughly similar to grade 5. I think A490 is roughly similar to grade 8. Also the original discussion specifically said single shear.

Table 5.1 in the referenced document is not allowable stress it's ultimate stress, it does not have a safety factor. In actual use in buildings you would add a 2.0 safety factor so that cuts the number in half to get to allowable. "Nominal strength" in structural engineering terms means ultimate strength.* Also that's a 2004 document, the values went up in 2009. Modern versions of the AISC manual have different values- 84ksi for shear through the bolt body instead of 75.

We've upped the stress level quite a bit by going from 1974 code to 2009 code and changing to a higher strength bolt so now 84,000 * 0.049 / 2,150 = 1.91H. There is no safety factor so it's on the verge of dropping the H. If you want to add a safety factor so you can safely stand under the thing then you are right about at 1 full H. If you redesign the small aircraft part to use double shear then you could hang 2H and safely stand under it.

*Terminology has gotten all screwed up these days. Many years ago we had steel design in allowable stress but ACI had just introduced their ultimate strength design code so concrete was designed in ultimate strength. Load factors were added to get to ultimate strength terms so we called them factored loads. Now the codes have load factors for allowable stress design so we can't use the terms factored loads anymore. AISC came out with their own new code for load and resistance factor design, their version of ultimate strength but they don't call it ultimate strength so not everybody uses the terminology of ultimate load. So the only somewhat universal terms would be strength level loads.

 

[cbrarick]

just remember, 1 square millimeter is equal to 10,000,000,000,000,000,000,000 barns......so how many of us could hit the broad side of a barn door?


hahaha

 

[Blast it Tom!]

That's the way to mix'em up there!

 

[NTP2]

View attachment 658666

That's the way to mix'em up there!

 

[Cape Byron]

 

[boatgeek]

View attachment 658724

Hardback or paperback books?

 

[tsmith1315]

View attachment 658724

That 12' is real, and she's less than 27 James Patterson books tall!

 

[Cape Byron]

That 12' is real, and she's less than 27 James Patterson books tall!

All the more impressive!

 

[tsmith1315]

All the more impressive!

She could jump onto my roof!

 

[Cape Byron]

She could jump onto my roof!

Another missed Onlyfans opportunity.

 

[Cape Byron]

 

[bjphoenix]

 

[Cape Byron]

 

[Cape Byron]

 

[Sandy H.]

View attachment 658937

I once knew a person who thought the Fl OZ meant 'full' ounces. I'm not sure of the validity of a 'partial' ounce, but once I figured out that concept, I have used it on occasion. I may add the 50 state option to my ounces moving forward. They seem pretty sad in Washington, though.

 

[Donnager]

View attachment 658945

95 km/h sounds better than 60 mi/h, I guess.