Nut, bolt, washer size guide?

[CyberBill]

I'm looking at replacing a wide array of nuts, bolts, screws, and washers on my frame due to them being rusted out and I've broken a handful. I'm using the parts manuals and the DMCH website, and then referencing the parts numbers across DMCH, DeloreanGo, DI, etc - but I've found that nuts and bolts from regular online sources is insanely cheaper, like 80%+!! Of course, I can't go and order random bolts and hope that they fit, so instead... I'm going through every nut and bolt that I've pulled off the car and measuring each one. I have done some searches, but haven't found anyone who has done this at a large scale on the car. Since I'm doing a full frame replacement, plus refurbishing the suspension and brakes, I'm going to cover a large portion of the car and I've got probably 100 nuts & bolts sized so far.

As an example - SP10223 are the bolts that hold the torque converter to the flex plate (auto transmission). The sites list the bolt as M10, and have a picture showing its roughly 3/4" long and A2 stainless, and the price is $5.51. I measured it - it's M10-1.5, 16mm long, and I can buy a stainless A2 replacement for $0.59 through BoltDepot.com.

Likewise, in a pinch if someone needs a bolt to get up and running and doesn't want to wait 3 days for shipping, they would be able to walk into a Lowes or Home Depot or whatever is nearby and pick up a replacement.

Would this be helpful to have as a resource? Is there anyone who would be interested in collaborating on it?

[MrChocky]

I'm looking at replacing a wide array of nuts, bolts, screws, and washers on my frame due to them being rusted out and I've broken a handful. I'm using the parts manuals and the DMCH website, and then referencing the parts numbers across DMCH, DeloreanGo, DI, etc - but I've found that nuts and bolts from regular online sources is insanely cheaper, like 80%+!! Of course, I can't go and order random bolts and hope that they fit, so instead... I'm going through every nut and bolt that I've pulled off the car and measuring each one. I have done some searches, but haven't found anyone who has done this at a large scale on the car. Since I'm doing a full frame replacement, plus refurbishing the suspension and brakes, I'm going to cover a large portion of the car and I've got probably 100 nuts & bolts sized so far.

As an example - SP10223 are the bolts that hold the torque converter to the flex plate (auto transmission). The sites list the bolt as M10, and have a picture showing its roughly 3/4" long and A2 stainless, and the price is $5.51. I measured it - it's M10-1.5, 16mm long, and I can buy a stainless A2 replacement for $0.59 through BoltDepot.com.

Likewise, in a pinch if someone needs a bolt to get up and running and doesn't want to wait 3 days for shipping, they would be able to walk into a Lowes or Home Depot or whatever is nearby and pick up a replacement.

Would this be helpful to have as a resource? Is there anyone who would be interested in collaborating on it?

Maybe. This is related to the "Frankenstein DeLorean Project" I brought up a few months ago:

http://dmctalk.org/showthread.php?18087-Website-Idea-DeLorean-Frankenstein-Project&highlight=frankenstein+project

I've also been replacing nots/bolts/washers, although not at your scale. Maybe 50 pieces over all to refresh. And yes, it can get expensive, although
I've only been purchasing a few pieces in a given size for places that are easy to reach, and to get familiar with the car.

What I've found is that with the previous work on the car, the sizes chosen perhaps weren't real picky, and used whatever worked, so items in the car don't always match what's in the parts manual.

[CyberBill]

Maybe. This is related to the "Frankenstein DeLorean Project" I brought up a few months ago:

http://dmctalk.org/showthread.php?18087-Website-Idea-DeLorean-Frankenstein-Project&highlight=frankenstein+project

I've also been replacing nots/bolts/washers, although not at your scale. Maybe 50 pieces over all to refresh. And yes, it can get expensive, although
I've only been purchasing a few pieces in a given size for places that are easy to reach, and to get familiar with the car.

What I've found is that with the previous work on the car, the sizes chosen perhaps weren't real picky, and used whatever worked, so items in the car don't always match what's in the parts manual.

That's great! I think a crowd-sourced project like that would be awesome. I have a few other projects going on at the moment, but perhaps I can bring something to life in mid-2021 - I have all of the web skills necessary to make that work.

You are right about the work from the PO - I've found a bunch of replacement bits that are stainless and look much newer than 40 years, plus a bunch of places where they stacked 2-3 washers to make a bolt work.

So far I've got 104 unique parts measured, ~350 total items, and I've marked roughly half for replacement. Today I'll measure all of the suspension and brake components, probably another 20 items. At some point I also need to match up the measurements of a bolt to a particular part #.

[DMC-81]

That's great! I think a crowd-sourced project like that would be awesome. I have a few other projects going on at the moment, but perhaps I can bring something to life in mid-2021 - I have all of the web skills necessary to make that work.

You are right about the work from the PO - I've found a bunch of replacement bits that are stainless and look much newer than 40 years, plus a bunch of places where they stacked 2-3 washers to make a bolt work.

So far I've got 104 unique parts measured, ~350 total items, and I've marked roughly half for replacement. Today I'll measure all of the suspension and brake components, probably another 20 items. At some point I also need to match up the measurements of a bolt to a particular part #.

One thing to be aware when putting this list together is the strength of a given bolt. It is marked on the head. While stainless steel looks great, it is not a high strength material. I would take care to avoid using SS where a high strength application is called for. Also, be aware of galvanic corrosion where two dissimilar metals are used. A good example is a stainless steel bolt in an aluminum rivnut. They will weld together over time.

[CyberBill]

One thing to be aware when putting this list together is the strength of a given bolt. It is marked on the head. While stainless steel looks great, it is not a high strength material. I would take care to avoid using SS where a high strength application is called for. Also, be aware of galvanic corrosion where two dissimilar metals are used. A good example is a stainless steel bolt in an aluminum rivnut. They will weld together over time.

Yes, this is a great point! I'm marking my data sheet with whatever markings they have on the bolt (if I can read them!) - it seems that most of the stock bolts are rated as 8.8 and appear zinc coated as best I can tell. I tried using a magnet on bolts to see if they were magnetic, and thus stainless steel, but it turns out that doesn't actually work. I have brand new stainless bolts from DeloreanGO that are quite magnetic, so apparently my "common knowledge" was just flat wrong. Of course, I'm pretty sure all of the SS bolts on my car are non-stock.

[dn010]

Certain grades of stainless are magnetic so you can't go by that. When I did my frame swap, I wrote down all the bolt sizes for the frame and ordered them online, if I can find where I wrote it down I will gladly post it. I used stainless bolts on things like horn brackets, radiator brackets and other things that don't require high strength. There are certain bolts like the fuel tank closing plate that I could not get in the proper length, these I had to buy longer and cut them down to work.

[mr_maxime]

A2 stainless is close to class 8.8 steel. 100ksi VS 110ksi. Obvious place to not use standard SS bolts are the axles and trailing arms.

One thing I want to know is how much strength is lost once the bolt starts corroding. The stainless one may be weaker initially, but you won't have to worry about it rusting and breaking.

[David T]

If the hardware you bought was Chinese stainless (and you bought stainless because it doesn't rust) you will be disappointed. Not only will it rust, it isn't very strong.

[David T]

If the hardware you bought was Chinese stainless (and you bought stainless because it doesn't rust) you will be disappointed. Not only will it rust, it isn't very strong.

Also you can't trust the grade markings if it is Chinese. Probably best to clean up the original hardware and replate it if it isn't badly rusted.

[mr_maxime]

If the hardware you bought was Chinese stainless (and you bought stainless because it doesn't rust) you will be disappointed. Not only will it rust, it isn't very strong.

Good luck finding fasteners not made in China or its neighboring countries. Even hilti makes their stuff in China.

we used threaded rod for stabilizers on our thermal oil pipelines at my previous job and we spent quite a lot of time going over strength, material grade and source. This was critical application so we wanted to be sure it would not fail.

[David T]

Counterfeit hardware got into the Bell Helicopter parts system and caused crashes. Inferior metal used to make brake rotors has gotten into the automotive parts supply. Ordinary metal is mismarked as graded (hardened). It is a BIG problem. That is why I suggested to reuse the hardware you got, you know it is good. The only bolts I would recommend replacing are the TAB's. The rest can be tumbled and plated. If you think the problem is only hardware, try buying bearings!

[mr_maxime]

Counterfeit hardware got into the Bell Helicopter parts system and caused crashes. Inferior metal used to make brake rotors has gotten into the automotive parts supply. Ordinary metal is mismarked as graded (hardened). It is a BIG problem. That is why I suggested to reuse the hardware you got, you know it is good. The only bolts I would recommend replacing are the TAB's. The rest can be tumbled and plated. If you think the problem is only hardware, try buying bearings!

I am well aware of counterfeit Chinese steel. I don't think it's as common of a problem as you make it out to be. Just dont buy unbranded bolts from ebay. I'll take my chances on brand new hardware from a reputable source over corrosion damaged bolts.

[Bitsyncmaster]

I am well aware of counterfeit Chinese steel. I don't think it's as common of a problem as you make it out to be. Just dont buy unbranded bolts from ebay. I'll take my chances on brand new hardware from a reputable source over corrosion damaged bolts.

They also can make the counterfeit hardware with the brand names on the parts. I have got counterfeit electronic components from Ebay that were labeled just like the real thing. I only buy from big name US retailers now.