M5 x 0.8 threaded bolts... Are there no standards?
 

Pardon my rant, but...

I have M5 x 0.8 bolts on probably every bicycle I own. They hold on the fenders, water bottle cages, racks, and so on. I like them.

And I like being able to use Allen wrenches on them.

But some are stainless steel, some are black, some are chromed, and some are just rusty. Worse, they take every imaginable size wrench from 2 mm to 5 mm. Many of the smaller ones no longer take any known Allen wrench size, the hexagonal hole having gotten rounded out somehow.

I would like to replace them all with some standard size, in stainless steel. Any suggestions where to get good ones?

Ace Hardware. They are a hardware store, not a home improvement store...There is a difference.

Ace has a pretty remarkable stainless metric fastener selection. McClendon's might be helpful if you have one near by.

Then of course, Amazon if you need something particularly long. https://www.amazon.com/gp/aw/d/B06XK...?ie=UTF8&psc=1

McMaster Carr has just about every variation of hardware available.... https://www.mcmaster.com/

It's rather handy to just pick up a box of 10mm M5 socket head bolts in stainless, along with washers, nuts, etc, as needed.
Browse through their offerings and you'll be amazed at all the variations!

Steve in Peoria

Hey, are you trying to disrupt your history of having every tool except for the correct one in your kit?

https://www.worldwidecyclery.com/pro...yABEgLOUPD_BwE

$17 for 50 is a good deal, I did not search for 8mm.

+1 for Ace. They carry a commendable selection of Metric and SAE hardware in various materials/finishes.
I personally prefer the button head variations over socket heads.

snowed in?
 

Here we have a Marine Hardware store with lots of Stainless steel hardware, because the Commercial fishing industry they serve is operating at Sea..



Industrial fastener stores offer boxes of hundreds..

cap screw button head, flat head.. or use all the same and in only one length?







.....

You can say the same thing for every bolt of a given thread size. The threads will be the same but there's a huge variety of materials, finishes, heads, drives and lengths. If you want consistency, buy bulk and start replacing. My preferred source was Fastenal, until my local store stopped selling directly to the public. Now, they'll only deal with businesses and contractors.

I have used Bolt Depot.

https://www.amazon.com/TOPINSTOCK-St.../dp/B07119C2VW

50 for $8.99 delivered. Make sure to use a bit of lubricant when going into aluminum with stainless steel fasteners to prevent galling.

I just received a batch ordered through Amazon. My neighborhood hardware store shut down and it's a hassle to get to the next closest hardware store. So I ordered this container of 110 bolts and nuts for $10. Stainless steel socket cap hex heads -- easier to start by hand, and my multi-tools already have the right tool.

I was re-doing the fenders and racks on one bike and realized it was a hodge podge like the OP described -- a mess of stainless and rusted carbon steel, socket cap hex heads, button heads, Philips, a couple of slotted screws, a couple that needed an 8mm wrench (probably the strongest but not as convenient). Wotta mess.

I settled on socket caps with knurled edges because even if the hole gets buggered it's still possible to remove them with pliers or Vise Grips.

I'll probably order another batch of button heads to avoid interfering with other nearby stuff. Only problem with button heads is there's nothing to grab to remove one that's jammed, so we'd need to slot them or file the edges to have something to grab. But the knurled socket caps are handy for most stuff.

I also need to order a tap to chase the threads on one lug that was already buggered when I bought the bike used. Didn't notice it until I removed the fenders and racks but the M5 bolt was basically just jammed, crammed and cross-threaded into a buggered lug. I might need a tap to thread it to the next size up.

If you need washers, solid or lock washers, it might be necessary to order those separately. My $10 kit didn't include washers.

Ditto Loctite for instances where there isn't enough room for even a single thin washer.

I actually like the various options. Different applications are best met with different style fasteners I like hex heads better for FD cable clamps on bikes with close rear wheels. Allen heads for the same clamp on the RD.

Ben

The non metric Blackburn hardware is the most annoying, that stuff is just everywhere in the bolt bins. Metric thread, but they take an American standard allen wrench.

That's pretty much as convenient as working on my '97 Camaro. "Hey, would you like to need SAE, metric, AND Torx bits on your car, perhaps on a single component??? Have we got a era of vehicles for you to choose from!"

To the OP, yeah, McMaster-Carr is fantastic. So much to choose from! And when you're working on any CAD projects and need bolt models or specs, they're right there.

If local hardware stores are available and good, then that's always nice because you can actually hold them in your hand and find thin washers to go with them etc. McClendons, spoken like someone who lives in the greater Seattle area. ;)

I have grown to accept the silliness of GM fasteners. Blame it on Roger Smith who wanted to go metric. He was able to push Saturn that way.
The rest of the company resisted as they could. One reason was in the USA metric fasteners were much more expensive compared to SAE. The bean counters often prevailed.

Now, Volkswagen... Spline drive, triple square drive.... some other standard that kind of looks like torx, but has 5 points...
If you have ever taken apart a 10-12 year old Jetta interior... you will be cursing the quantity of times you must change drive bits. And amazed at the wide range of fastener diameters heads and lengths. Stupid.
Diabolical.
Expensive, if they put some thought into it, they could reduce the cost of assembling a vehicle by a very measurable amount.
The probable best in class is Mazda. Followed by Toyota. they tried to really use the same style and size of fastener as much as possible. A #2 phillips and a 10 mm socket and you can do a lot quickly.

Tesla? Oh dear, now there is a short position profit "investment".

The Japanese tend to nail that stuff really well. Germans...being Germans. I think I'll take my three drive standards + crummy interior fasteners over a Jetta's any time.

...I'll also take the not insignificant V8 horsepower and torque, too. That thrust and the accompanying soundtrack help dissolve much frustration. :)

We have a local-to-us family-owned hardware store, not affiliated with any chain. They've been around for about a hundred years and have a remarkable selection of even the most difficult to source bolts and other fasteners, all sorted and stowed away in drawer after drawer in aisles of antique wooden storage. Used to be that every town or section of the city had a place like this and we're fortunate to still have ours - there's a similar place in the next town over from here. Anyway, it's not unusual for me to visit them in search of some odd or end, and they nearly always have what I'm looking for, no matter how esoteric.

I don't buy in bulk - there's no need, they're a quarter mile away. They sell nuts and bolts one at a time, so if I need an M5 it sets me back seven cents. A matching washer? Another two or three cents. It actually keeps those stray pennies in my car sort of relevant. I have no idea how they stay in business with me buying things 23 cents at a time.

Not at all. If I can ensure that all the bolts on my bike have the same size head, I will know exactly which one not to bring. It leaves less to chance this way.

IIRC, those weren't metric thread, but rather SAE 10-32, which is close enough to work in a 5 x 0.8mm hole. And they came with a 1/8" Allen key.

That would make more sense, also means I have a bunch of 10-32 nylock nuts in my misc metric hardware.

Hmm :foo:

Time to order some more bolts.

You know, if I had my preference, I'd standardize everything to 5mm Allen wrenches. That seems to be one of the most versatile bike wrench sizes.

I think they're called "socket cap" or "socket head" with the cylinder shaped heads. Titanium also has "tapered head" bolts that are popular.

These look like they will work well. Unfortunately I can't tell the wrench size. They appear to be 4mm or 5mm, but not specified.
https://www.ebay.com/itm/10X-Bike-Bi...w/253349799400

For the Amazon users, and Knurled (4mm wrench).
https://www.amazon.com/M5-0-80-Socke.../dp/B01L0E1B2U

Actually, thinking about it, there may be strength benefits of going with one wrench size smaller than the bolt size, so 4mm? Although, I don't think I've ever had a bolt sheer at through the wrench socket.

I really don't like the round head 5mm bolts with say 2 or 3mm Allen Wrench sockets.

​​​​​​
That's the problem with a lot of these.

I would be fine with either, but I think I have a lot of 4 mm ones already, so I'd start there.

there isn't a standard for the wrench size, unfortunately. I recently back-filled my selection of 5 and 6mm bolts from McMaster, and they are shipping Chinese hardware now instead of U.S. made. At least for the stainless bolts I got. They seem fine though.

I would just pick one bolt style. I like button head screws if they will work, so that's another size.

And actually, these bolts are all China sourced and not that great of thread quality, so I recommend lubricating just in general. I use a copper-free anti-seize and a $13 bottle will last me until I die..