This may be dumb but... which fasteners and when to use them?

[tirwin]

This may be a dumb question but that's never stopped me before.

I'm getting ready to do some suspension work on the car and it got me thinking that I wish I had a better understanding of when to use certain types of fasteners.

There was a similar thread recently on when to use anti-seize and which type of loctite to use for different jobs that was pretty useful.

That got me thinking about fasteners. How do you tell grades? Which grade is right for which jobs like chassis/suspension vs exhaust or engine? Which material (zinc, steel, brass, etc.) for which jobs? I know dissimilar metals can cause galvanic action.

I know there is a lot of engineering that goes into this stuff so if anyone can share any info or "rules of thumb" that could help a DIYer that would be great.

[javadog]

Use what Porsche put on there, originally. We don't have the engineering data to calculate any loads, so there's no real good way to reverse engineer it. You'll generally find unmarked bolts, bolts marked with a property class of 8.8, some 10.9, some 12.9. All will have different torque values, so a set of service manuals and spec books for your car will be needed.

These fasteners will be steel. You won't find zinc fasteners and if there are any brass ones, they'll likely only be things like interior trim screws, if there are any at all.

JR

[tirwin]

Thanks, JR.

I found this chart from BoltDepot.com



I don't think the PET specifies which types of bolts were used in various places, so I guess you just have to inspect each one on a case-by-case basis.

Speaking of torque values. I've seen people say many times that the torque values published in some places like the Bentley manual is incorrect. Does anybody know if Bentley ever published an addendum? How do you know which ones are wrong and which ones are right?

[tijnes]

The pet parts list will most times specify which size fasteners to use The thing id like to know is when to use the various washers (lock,wavey,schnorr etc) and or lock nuts. Those are not specified afaik. Is there logic to that?

Thanks
Martijn

[tirwin]

Originally Posted by tijnes

The pet parts list will most times specify which size fasteners to use

Size, yes. But I don't think it specifies the grade.

I wish there were pre-packaged sets of fasteners and washers available for certain jobs. One click and everything you'd need in the your cart. There is nothing worse than burning time because searching through your junk box or making a trip to the hardware store for that one little nut, washer or bolt you're missing. All those little interior trim screws and stuff like that.

Originally Posted by tijnes

The thing id like to know is when to use the various washers (lock,wavey,schnorr etc) and or lock nuts. Those are not specified afaik. Is there logic to that?

Good question! I have no idea, but agree it would be good to know.

[RWebb]

Originally Posted by tijnes

The pet parts list will most times specify which size fasteners to use The thing id like to know is when to use the various washers (lock,wavey,schnorr etc) and or lock nuts. Those are not specified afaik. Is there logic to that?

Thanks
Martijn

there is a thread on lock washers - think I started it

on a later thread I posted and/or linked to a more recent study showing that lock washers do not lock well, in fact, they can be worse than nothing

use a thread-locker; if a torqued fastener then use the green wick-in product


too bad Jim Sims is no longer with us...


and BTW, I just replace all the fasteners with titanium

I bet some have tired to drill holes in their bolts too...

[Ayles]

I have been buying new on project basis. I buy from pelican on the important stuff (Trans and engine related). All the other stuff I have been buying from other fastenall store by my office. They probably laugh every time I stop buy and only buy 5 nuts and washers for a specific job. I always bring the old hardware in for reference.

There is a guy on eBay selling a set of fasteners for 911 interiors.

[javadog]

You can buy hardware assorments from Wurth, Eagle Day, etc. I don't use the local hardware store stuff, as a lot of it is junk.

JR

[javadog]

Originally Posted by RWebb

and BTW, I just replace all the fasteners with titanium

I bet some have tired to drill holes in their bolts too...

I have a lot of titanium and aluminum fasteners, They don't often get used on a Porsche, usually only on a motorcycle. Lot's of them are drilled, too.

$$$

JR

[mazing3]

Hey Tirwin,

I stumbled upon the mother of all fastener apps for this kind of thing it's called iEngineer. I

t's free but 1.99 for the in app upgrade to get metric but it's worth it. You select your diameter, thread pitch, head shape and grade and then it gives you all kinds of useful data. Shear force, tensile strength, proof load, and a whole bunch more that I don't really understand. But they have definitions for all that in the app. It even gives the recommended torque for each.

Also has everything related to choosing the right drill bit for tapping too. I love this thing so far.

[tirwin]

Originally Posted by mazing3

Hey Tirwin,

I stumbled upon the mother of all fastener apps for this kind of thing it's called iEngineer. I

t's free but 1.99 for the in app upgrade to get metric but it's worth it. You select your diameter, thread pitch, head shape and grade and then it gives you all kinds of useful data. Shear force, tensile strength, proof load, and a whole bunch more that I don't really understand. But they have definitions for all that in the app. It even gives the recommended torque for each.

Also has everything related to choosing the right drill bit for tapping too. I love this thing so far.

great tip!

[RWebb]

BTW - there are few high-strength fasteners used on a 911

should be an list of some in an old thread, but...

high strength fasteners that come to mind include:

901 & 911 trans. diff. bolts are special, maybe not high strength

rod bolts

not sure re ball joint stuff - you want the newer wedge pin types anyway

[mcaterino]

Below is the list I compiled for my restoration. I won't swear by its historical accuracy, but it's based on a lot of sources, here as well as PET and workshop manuals.

I never got around to cleaning this up completely, but the numbers in parentheses refer to the numbers in the PET. For instance, the ball joint retainer bolt is labelled #22 on the exploded diagram of the front strut assembly.



If there are questions about this I can try to fill in details.

Mike

PS - Just realized I have to change my signature. I recently moved to South Carolina. Have to look for some southern Pelicans!

[74-911]

Originally Posted by tirwin

I wish there were pre-packaged sets of fasteners and washers available for certain jobs. One click and everything you'd need in the your cart.

I just completely rebuilt the front suspension on the '74. To be able to order a pre-packaged set of all the bolts and washers (cadmium or yellow zinc) used in the front suspension for the control arms, sway bars, cross-member, steering rack, etc. would have been wonderful to say the least. The front and rear suspensions hardware in the above post by MCaterino would be a great place to start.

[tirwin]

Mike,

That's exactly the kind of thing I'm talking about. Excellent work!

[rwest]

I bought a prepackaged set of hardware from Elephant racing for my rear suspension. Those 12.9 bolts are virtually impossible to find locally.

[Lyle O]

Try Belmetric.com...you can buy small quantities of metric nuts and bolts, up to and including grade 10.9, at all lengths and pitches. Great resource...

[proffighter]

Originally Posted by javadog

I have a lot of titanium and aluminum fasteners, They don't often get used on a Porsche, usually only on a motorcycle. Lot's of them are drilled, too.

$$$

JR

Aluminum and drilling? ts ts ts

No idea what you are talking about

[RD911T]

Originally Posted by mcaterino

Below is the list I compiled for my restoration. I won't swear by its historical accuracy, but it's based on a lot of sources, here as well as PET and workshop manuals.

I never got around to cleaning this up completely, but the numbers in parentheses refer to the numbers in the PET. For instance, the ball joint retainer bolt is labelled #22 on the exploded diagram of the front strut assembly.



If there are questions about this I can try to fill in details.

Mike

PS - Just realized I have to change my signature. I recently moved to South Carolina. Have to look for some southern Pelicans!

Sent you a PM regarding getting a copy of this.

Tom