A Tale of Three Calipers, Tell me about different RIBE hardware Options

[zoomCat]

I'm putting together a pair of rear calipers for a six, which the previous owner had replaced with 911 rears to get the vented disks. He didn't keep the originals, it was back in the 80's and nobody cared.
Here's what I've got so far:



On the left is a rebuilt stock 914/6 left rear. The plan is to add a spacer for vented disks.
In the middle is a 914/6 right rear, which I got years ago that already has a spacer. It will be rebuilt.
On the right is what I think is a right rear Ferrari 308 caliper, because the bleeder is in the wrong place. It can be a donor if absolutely needed. The rears the previous owner had installed are the first candidate for donors.

My question today is about the RIBE hardware.



On the left is the rebuilt stock, on the right is /6 caliper that had a spacer added. The fasteners on the left have sloped shoulders, while the other has more square shoulders, which I see on the front A and M calipers I've got.

What was original, either for the stock calipers or the GT calipers?
Is there any functional difference? Esthetically I'd like to get it all matching and correct before I send it all off to PMB, but that depends on availability.

[gandalf_025]

Then again, you could always make your own
hardware and spacers …. These worked well for
quite some time..

[Eric_Shea]

Then again, you could always make your own
hardware and spacers …. These worked well for
quite some time..

This is a perfect example of what “NOT” to do (IMG:style_emoticons/default/biggrin.gif)

If I recall, we fixed this. (If I’m not wrong, they’re probably now the correct GT calipers pictured above in post #12)

Wrong size spacers and wrong size aftermarket fasteners that had no strength and no right to be on a brake caliper. (IMG:style_emoticons/default/wink.gif)

[Superhawk996]

This is a perfect example of what “NOT” to do (IMG:style_emoticons/default/biggrin.gif)

Setting aside the question of fastener tensile strength and suitability for application.

If they didn't have the tools and/or couldn't be bothered to trim the fasteners to the proper length, I have to wonder what else they couldn't be bothered to do properly when working on brakes. (IMG:style_emoticons/default/sheeplove.gif)

I would never trust my life to workmanship like that. (IMG:style_emoticons/default/slap.gif)

[Eric_Shea]

This is a perfect example of what “NOT” to do (IMG:style_emoticons/default/biggrin.gif)

Setting aside the question of fastener tensile strength and suitability for application.

If they didn't have the tools and/or couldn't be bothered to trim the fasteners to the proper length, I have to wonder what else they couldn't be bothered to do properly when working on brakes. (IMG:style_emoticons/default/sheeplove.gif)

I would never trust my life to workmanship like that. (IMG:style_emoticons/default/slap.gif)

Those were a hot mess. Duly noted though that Home Depot fasteners are OK to use on brake calipers. (IMG:style_emoticons/default/biggrin.gif)

[Superhawk996]

Duly noted though that Home Depot fasteners are OK to use on brake calipers. (IMG:style_emoticons/default/biggrin.gif)

Just to be clear, I was not lobbying that these fasteners were OK to use. (IMG:style_emoticons/default/stirthepot.gif)

Not just a question of tensile strength. Due to the nature of the caliper geometry, the fasteners are exposed to bending loads which is something you don't want but can't be avoided in this application.

Knowing that there are bending loads involved, surely don't want a full threaded shank in there where bending loads are imparted on the root of the threads that can act like a stress riser. Would also want a rolled thread vs. something with a cut thread form. Rolled threads being less of a stress riser . . . to a degree.

Likewise, don't buy your highly stressed SHCS fasteners at Home Depot. If it's critical enough to warrant a grade 12.9 fastener, I'm not getting it at Home Depot. (IMG:style_emoticons/default/happy11.gif) I'll also add there are fastener grades above 12.9 and I honestly don't know what the Ribe fasteners are but assuming they are AT LEAST 12.9 but may be even higher.

For those that are interested Eric has a wonderful website on caliper rebuilds complete with a picture of the proper Ribe fasteners. (IMG:style_emoticons/default/first.gif)

https://www.pmbperformance.com/brakehowto.html

[PatMc]

Duly noted though that Home Depot fasteners are OK to use on brake calipers. (IMG:style_emoticons/default/biggrin.gif)

Just to be clear, I was not lobbying that these fasteners were OK to use. (IMG:style_emoticons/default/stirthepot.gif)

Not just a question of tensile strength. Due to the nature of the caliper geometry, the fasteners are exposed to bending loads which is something you don't want but can't be avoided in this application.

Knowing that there are bending loads involved, surely don't want a full threaded shank in there where bending loads are imparted on the root of the threads that can act like a stress riser. Would also want a rolled thread vs. something with a cut thread form. Rolled threads being less of a stress riser . . . to a degree.

Likewise, don't buy your highly stressed SHCS fasteners at Home Depot. If it's critical enough to warrant a grade 12.9 fastener, I'm not getting it at Home Depot. (IMG:style_emoticons/default/happy11.gif) I'll also add there are fastener grades above 12.9 and I honestly don't know what the Ribe fasteners are but assuming they are AT LEAST 12.9 but may be even higher.

For those that are interested Eric has a wonderful website on caliper rebuilds complete with a picture of the proper Ribe fasteners. (IMG:style_emoticons/default/first.gif)

https://www.pmbperformance.com/brakehowto.html

Agreed.

I've always assumed they were 12.9 strength simply due to the fact that the later calipers using hex bolts are 12.9...and I'm pretty sure the non-button heat Ribe screws are marked 12.9 (at least some of them)...and they're the same size and everything else. The only thing that changes is the thread engagement (1x diameter rule doesn't apply in cast iron).