Common Vehicle Fastener Sizes

[Kscardsfan]

Might be a silly question, but does anyone know of a reference or website that lists the most commonly encountered fasteners on a given vehicle? I'm trying to get my shop set up for more efficient fleet maintenance so we don't farm out so much of our work to shops etc. especially normal preventative maintenance work like oil changes, brake jobs etc. Thank you all in advance.

 

[Radio Flyer]

What type of fleet?

 

[WWheeler]

One of the few 100% guarantees in life are that if you are missing a particular size that size fastener will show up on whatever you are working on just to spit in your face. Set yourself up with no-skips.

 

[bwringer]

It varies wildly, and depends on type of machine, nationality, brand, and make/model. Some brands are quite consistent, some are complete mongrels. And no, I've never seen anything like a list for a given vehicle; even the service manuals never tell you the tools needed or fastener specs, which I've always felt would be wonderfully useful.

Are you trying to set yourself up for all the tools needed, or build up a fastener collection? Or both?


I can say that Asian machinery is generally far more consistent in this regard; that's all I work on, so, for example, all my 11, 13, 15, 16, and 18mm tools are relegated to a secondary toolbox. It makes my usual work go a bit faster with the stuff I never need out of my way.

As to fasteners, I've build up a rather large collection over the years simply by noting and measuring what I take off, then ordering a box of each from McMaster-Carr. Costs a bit, yes, but in the end it's saved so much time, expense, and aggravation over trips to the hardware store that it's well worth it.

I also make note of any specialty fasteners I encounter, and any that aren't perfect get replaced with OEM. For example, when I buy a new-to-me motorcycle, the fairing fasteners are almost always chowdered. WAY too many owners and techs don't know how they work, or just plunge in with crappy tools. A fresh set doesn't cost that much and greatly improves my overall quality of life now and in the future.

There are also a few suppliers specializing in hardware for motorcycles and powersports.

 

[WWheeler]

Even if you are SURE that you have every size tool to fit every OEM fastener for any certain make/model you are going to run into instances where someone has used an aftermarket fastener. A bolt or nut was missing and replaced with whatever they had that fit. Some aftermarket item was installed. Something got stripped and drilled and tapped larger. A fastener is so rusted you need to hammer on a size smaller. Etc.

 

[Wrench97]

5mm through 24mm, 27mm, 32mm, 34mm, 36mm.
Sockets deep and shallow, combo wrenches, ratcheting wrenches, should about cover it until you get SAE bolts and nuts somebody used instead of metric.

 

[Kscardsfan]

It’s more so I can write up job sheets etc for guys to do PM work on stuff. We’re getting full sets of no skip tools here on the budget cycle so it should be fine in that regard. But I’d like to be able to say if you’re working on the 2012 Ram 1 ton, grab XYZ sockets and wrenches and get after it.

 

[Kscardsfan]

What type of fleet?

Trucks, tractors, lawnmowers, some Chevy Malibus. You name it it’s here.

 

[mikedodge]

thats too much of a range to have specific stuff. Whoever is doing the work should already know what the most common tools being used are and what needs to be bought to fill in the gaps.

 

[bb29510]

I hate fleet mechanics, my truck is a fleet truck, so you go in for a nail and he put on four tires without permission, because it has a fleet card, the old tire had 75% thread left, go in for oil change and he does brake job which he just did last week, it has fleet card. fleet pays for everything

 

[Kscardsfan]

thats too much of a range to have specific stuff. Whoever is doing the work should already know what the most common tools being used are and what needs to be bought to fill in the gaps.

I inherited the mess and I am trying to give myself a leg up on the work to be done. The fun part is I have to have SAE and metric no matter what by the sheer age and diversity of the vehicles and equipment we run. So at least I can justify why I need 2 sets of wrenches, sockets etc.

 

[mikedodge]

You'd probably need something better quality being a shop but I got tired of missing misc oddball bits and bought a set similar to this. Along with a wrench set it covers a lot of what regularly need.

General PDP Template

www.canadiantire.ca

 

[Tools4Me]

I'm not sure knowing all the common fastener sizes on a certain vehicle will be as helpful as you may be thinking, but I still might be able to help. I make two types of laminated cards for each vehicle or piece of equipment I work on. One card is a general info card. If it is a car for instance, it contains info like the wiper blades I use, oil filter part number, oil type and capacity, headlight bulb part number, brake light bulb part number, lug nut size, lug nut torque, the type of antifreeze the vehicle takes, brake pad part numbers and min pad thickness spec, brake rotor part numbers and brake rotor minimum thickness spec, transmission fluid type, serpentine belt length and part number, power steering fluid type, brake fluid type, wiper fluid capacity, etc. That gets me started on any quick problem that comes up or any small part I might need to buy. I keep that card in my tool chest or in the vehicle's glovebox at all times.

I also make small laminated cards that I keep in my shop which tell every spec I need to know and every tool I need to grab to do a single job, like changing the oil on a specific vehicle. The oil type, capacity, oil filter part number, drain plug socket size, plastic belly pan bolt size, which screw on filter pliers work best for that filter, which funnel works best for refilling the oil, the drain plug torque spec, the instrument panel oil change reminder light reset procedure, etc.

I write all that info down on a piece of paper when I do an oil change on that vehicle for the first time, then I quickly type it out and laminate it. I probably have 15-20 minutes of time invested in each job specific laminated card I use. Next time, I grab that laminated card and quickly source the filter, oil, tools, paper towels, drain pan, etc. and put it all in place before I touch a single bolt. Most of the tools I grab are put into a large carry tray (a repurposed stainless oven roasting pan with handles) that is set under the vehicle right next to where I will be working. I slip under the vehicle and don't come out until it's time to put new oil in the top of the engine. No time is wasted hopping out from under the vehicle here and there to grab something I forgot. I also have cards for things like lawnmower blade sharpening, equipment winterizing procedures, etc.

Common maintenance tasks are where your time savings will quickly add up using reference cards or something similar. Even 5 minutes saved on each oil change adds up when many people likely do 20-40 oil changes over the time they maintain that vehicle for themselves or for someone else. If you have multiple duplicate vehicles in a fleet that all have the same oil change procedure your time savings will magnify even more.

 

[Dave455]

Did you mean the actual fastener sizes, or the appropriate wrench sizes.

Most vehicles with metric fasteners will use Metric M5, M6, M8, M10, M12 etc.

The actual hex sizes will vary with the exact standard.

German DIN will use 8, 10, 13, 17 etc

ISO / British will use 8, 10, 13, 16 etc

Japanese JIS will use 8, 10, 12, 14 etc

American ANSI uses 8, 10, 13, 15

So, if you know the origins of the vehicles you are working on you should know the sizes needed, but…

Some standards are evolving - German DIN is gradually coming in line with ISO, so older vehicles will have 17’s and 19’s, later will have 16’s and 18’s.

Sometimes sizes will be different to what’s expected, depending on what fasteners were sourced.

These are the “standard” sizes. “Heavy” fasteners use different sizes, so do the non favoured sizes such as M7, so do many specialised fasteners.

And of course anything might have been switched around in a vehicles life!

 

[Kscardsfan]

I'm not sure knowing all the common fastener sizes on a certain vehicle will be as helpful as you may be thinking, but I still might be able to help. I make two types of laminated cards for each vehicle or piece of equipment I work on. One card is a general info card. If it is a car for instance, it contains info like the wiper blades I use, oil filter part number, oil type and capacity, headlight bulb part number, brake light bulb part number, lug nut size, lug nut torque, the type of antifreeze the vehicle takes, brake pad part numbers and min pad thickness spec, brake rotor part numbers and brake rotor minimum thickness spec, transmission fluid type, serpentine belt length and part number, power steering fluid type, brake fluid type, wiper fluid capacity, etc. That gets me started on any quick problem that comes up or any small part I might need to buy. I keep that card in my tool chest or in the vehicle's glovebox at all times.

I also make small laminated cards that I keep in my shop which tell every spec I need to know and every tool I need to grab to do a single job, like changing the oil on a specific vehicle. The oil type, capacity, oil filter part number, drain plug socket size, plastic belly pan bolt size, which screw on filter pliers work best for that filter, which funnel works best for refilling the oil, the drain plug torque spec, the instrument panel oil change reminder light reset procedure, etc.

I write all that info down on a piece of paper when I do an oil change on that vehicle for the first time, then I quickly type it out and laminate it. I probably have 15-20 minutes of time invested in each job specific laminated card I use. Next time, I grab that laminated card and quickly source the filter, oil, tools, paper towels, drain pan, etc. and put it all in place before I touch a single bolt. Most of the tools I grab are put into a large carry tray (a repurposed stainless oven roasting pan with handles) that is set under the vehicle right next to where I will be working. I slip under the vehicle and don't come out until it's time to put new oil in the top of the engine. No time is wasted hopping out from under the vehicle here and there to grab something I forgot. I also have cards for things like lawnmower blade sharpening, equipment winterizing procedures, etc.

Common maintenance tasks are where your time savings will quickly add up using reference cards or something similar. Even 5 minutes saved on each oil change adds up when many people likely do 20-40 oil changes over the time they maintain that vehicle for themselves or for someone else. If you have multiple duplicate vehicles in a fleet that all have the same oil change procedure your time savings will magnify even more.

That’s actually what I’m hoping to end up with. I want to speed up simple jobs and keep things rolling smoother. I’m also planning on printing out various job aides for maintenance issues on the physical facilities for things like plumbing, electrical etc.

 

[Fedwrench]

It’s more so I can write up job sheets etc for guys to do PM work on stuff. We’re getting full sets of no skip tools here on the budget cycle so it should be fine in that regard. But I’d like to be able to say if you’re working on the 2012 Ram 1 ton, grab XYZ sockets and wrenches and get after it.

Waay too much micromanagement there.

I can see having a PM checklist listing everything you want checked during a particular level PM service but, the tech doing the work should know what they need to do the job.

 

[Kscardsfan]

Waay too much micromanagement there.

I can see having a PM checklist listing everything you want checked during a particular level PM service but, the tech doing the work should know what they need to do the job.

I have to depend on student interns, volunteers and seasonal staff for my workforce. And my toddler is more competent than my maintenance guy, so I’m generating these sheets to CYA as well as generate a paper trail. Government work is its own challenge sometimes.

 

[bwringer]

Sounds like what you're doing is similar in principle to what many of us do; if it's a project that I might do again, or something that's not obvious at a glance, or info that might be needed for reassembly, I write the fastener sizes and other helpful info right there in the shop manual.

That said, I've never figured out why tool and fastener sizes are almost NEVER included in OEM and aftermarket shop manuals the first place. For example, the CV axle nut on my van requires a 12 point 30mm impact socket, which is a bit of a specialty item. It's obviously a 12 point nut, and the manual says "12 point socket", but nothing in the shop manual tells you the &^%$#@! size you need.

One of my pet minor hatreds is motorcycle manuals that are completely silent on the socket size needed for the sprocket nut. This is one of the more common questions on motorcycle forums.

The parts diagrams for some brands sometimes mention the specs in the description (e.g. "M6x20") or embed a fastener's specs in the part number (for example, Suzuki motorcycles often do this: 01550-06407 is an M6x40mm bolt), but not always, and many brands do not do this at all.

To the original question, this type of documentation is mostly nonexistent, so you'd need to generate it yourself by doing the job yourself. Sad but true.

 

[VolvoRyan]

Doesn't really matter where the vehicle "came from" anymore. Components come from everywhere, so you'll see fasteners from every "standard". Hence you'll need all the sizes.... and hope you don't need all the "kinds". I've been lucky to dodge some fastener types.

-Ryan

 

[VolvoRyan]

That said, I've never figured out why tool and fastener sizes are almost NEVER included in OEM and aftermarket shop manuals the first place. For example, the CV axle nut on my van requires a 12 point 30mm impact socket, which is a bit of a specialty item. It's obviously a 12 point nut, and the manual says "12 point socket", but nothing in the shop manual tells you the &^%$#@! size you need.

I was thinking this would be a great idea myself. That would add value to a service subscription if it helped speed up flat rate. On the other hand, I've seen different "head" sizes and styles ("regular bolts" vs hex vs torx) for the same fastener on different vehicles of the same model. The thread is always the same, the head just changes. I swear I've seen 17, 18, *and* 19mm on old Volvo bell housings

-Ryan

 

[nadogail]

You will find it is impossible to have too many sizes of wrenches and screwdrivers when you are working on an undetermined assortment of vehicles.

As for spare parts; you can be assured that the one part you don't have is going to be the part you need to complete a job, someday.

 

[Kscardsfan]

You will find it is impossible to have too many sizes of wrenches and screwdrivers when you are working on an undetermined assortment of vehicles.

As for spare parts; you can be assured that the one part you don't have is going to be the part you need to complete a job, someday.

That’s when I knew I had hit middle age, when I started saving nuts, bolts and spare pieces in pickle jars etc for when I’ll need them for the next project.

 

[bwringer]

I was thinking this would be a great idea myself. That would add value to a service subscription if it helped speed up flat rate. On the other hand, I've seen different "head" sizes and styles ("regular bolts" vs hex vs torx) for the same fastener on different vehicles of the same model. The thread is always the same, the head just changes. I swear I've seen 17, 18, *and* 19mm on old Volvo bell housings

-Ryan

True; there's a lot of "whatever we had lying around that day" production variation in some makes.

In my experience, Asian machinery is far more consistent in this regard. Domestic and Euro brands are often weird parts mashups. I bet Toyota's partnership with BMW to make the Supra leads to some very aggravating times for Toyota techs.

I've found that some makes, for example Suzuki and Toyota, are far less likely to use special or oddball fasteners. Honda can throw some curveballs with **** like bespoke M6X32 fasteners instead of the standard M6x30 or M6x35.

And then, of course, you might have to deal with whatever some past owner or "perfeshunal mekanik" mangled. My vintage Suzuki came to me with all kinds of 1/4" and 5/16" fasteners from Grandpa's coffee can stuffed into M6 and M8 holes. Many still had traces of white or brown Briggs & Stratton paint on them... it took quite a long time to find and fix them all.

 

[Kscardsfan]

True; there's a lot of "whatever we had lying around that day" production variation in some makes.

In my experience, Asian machinery is far more consistent in this regard. Domestic and Euro brands are often weird parts mashups. I bet Toyota's partnership with BMW to make the Supra leads to some very aggravating times for Toyota techs.

I've found that some makes, for example Suzuki and Toyota, are far less likely to use special or oddball fasteners. Honda can throw some curveballs with **** like bespoke M6X32 fasteners instead of the standard M6x30 or M6x35.

And then, of course, you might have to deal with whatever some past owner or "perfeshunal mekanik" mangled. My vintage Suzuki came to me with all kinds of 1/4" and 5/16" fasteners from Grandpa's coffee can stuffed into M6 and M8 holes. Many still had traces of white or brown Briggs & Stratton paint on them... it took quite a long time to find and fix them all.

My dad bought a Jeep CJ-8 Scrambler brand new in 1982 and in my years of helping him work on it, I've encountered many situations where they used metric and SAE all over that truck. A friend of ours bought a 1983 Scrambler and we found random spots where metric fasteners were used that had been SAE on dads truck. By that point in time, I think AMC had largely stopped caring.

 

[VolvoRyan]

Didn't BMW do something like put metric heads on SAE-threads when they were building the old Buick V8's after buying Rover?

-Ryan

 

[Kscardsfan]

Didn't BMW do something like put metric heads on SAE-threads when they were building the old Buick V8's after buying Rover?

-Ryan

That sounds awful. And stupid.

 

[Junkdrawer Dog]

Didn't BMW do something like put metric heads on SAE-threads when they were building the old Buick V8's after buying Rover?

-Ryan

That happens more often than you might think, especially on legacy products. I used to build and service a line of industrial gearboxes that originated in Taiwan. The older tooling they had acquired was all set up to drill and tap SAE. Because they were widely sold throughout Asia, and Asia had gone metric long before, they had specialty fasteners made up with SAE threads and metric heads. Think 1/4-20 shank with a 10mm across flats head. This resulted in some screwed up boxes when customers tried to replace fasteners with an M6.

 

[Kscardsfan]

That happens more often than you might think, especially on legacy products. I used to build and service a line of industrial gearboxes that originated in Taiwan. The older tooling they had acquired was all set up to drill and tap SAE. Because they were widely sold throughout Asia, and Asia had gone metric long before, they had specialty fasteners made up with SAE threads and metric heads. Think 1/4-20 shank with a 10mm across flats head. This resulted in some screwed up boxes when customers tried to replace fasteners with an M6.

That sounds rough. Talk about having to know some detailed knowledge of your product.

 

[Wrench97]

Didn't BMW do something like put metric heads on SAE-threads when they were building the old Buick V8's after buying Rover?

-Ryan

I believe they just used a lot 11m, 13mm, 16mm & 19mm heads and people just assumed they were 7/16", 1/2", 5/8" & 3/4"

 

[Junkdrawer Dog]

That sounds rough. Talk about having to know some detailed knowledge of your product.

Google the term "mad metrics" as it pertains to MG automobiles. It's about Morris buying the old Hotchkiss (French) engine tooling. Said tooling was set up for an old, French standard for fine thread metric. Morris used special fasteners with the French, metric thread form with a Whitworth head size. This persisted to some extent for over 30 years.

 

[isb cornbinder]

One of the few 100% guarantees in life are that if you are missing a particular size that size fastener will show up on whatever you are working on just to spit in your face. Set yourself up with no-skips.

Fasten-All do a complete fastener set-up including the bins. They will restock as required.

 

[joe_pinehill1]

I recommend for suspension you only use manufacturer OEM fastener parts.

 

[Al Borland]

Didn't BMW do something like put metric heads on SAE-threads when they were building the old Buick V8's after buying Rover?

-Ryan

General Motors did this as well. Legacy engines in newer vehicles often got metric fastener heads for assembly, but they weren't about to retool the engine line to drill/tap in commie Metric sizes. this way, older parts fit newer engines and vise-versa.

 

[subroc]

So, are you planning on writing up procedures or technical direction or some kind of cheat sheets? Or, are you looking to show your mechanics that you are a smart ***?

 

[Kscardsfan]

So, are you planning on writing up procedures or technical direction or some kind of cheat sheets? Or, are you looking to show your mechanics that you are a smart ***?

I don’t have mechanics. I have an inept maintenance guy and my ranger and myself. My ranger and I literally changed the tires and oil on our tractors ahead of the winter storm in our gun belts and uniforms. If I can make up cheat sheets with the necessary tools, filters, chemicals and procedures etc for myself and my seasonal staff, interns etc it’ll take a ton of BS and stress off my plate by creating a check list for the job as well as for one of us to come in behind them and check that it was done right as well for spot checks on the work being done.

 

[BigLeagueSmoes]

Might be a silly question, but does anyone know of a reference or website that lists the most commonly encountered fasteners on a given vehicle? I'm trying to get my shop set up for more efficient fleet maintenance so we don't farm out so much of our work to shops etc. especially normal preventative maintenance work like oil changes, brake jobs etc. Thank you all in advance.

Maybe try ALLDATA. They are a huge resource to many mechanics. Some info I know you have to pay for. Not sure if it’ll help you but worth a plug

 

[Kscardsfan]

So, are you planning on writing up procedures or technical direction or some kind of cheat sheets? Or, are you looking to show your mechanics that you are a smart ***?

I should also add, we saw that the oil had last been changed in 2020 on both tractors, when they maintenance guy walked by and saw us working he said “oh yeah, I remember them doing that last time” and then went on to watch us working lol.

 

[bwringer]

I don’t have mechanics. I have an inept maintenance guy and my ranger and myself. My ranger and I literally changed the tires and oil on our tractors ahead of the winter storm in our gun belts and uniforms. If I can make up cheat sheets with the necessary tools, filters, chemicals and procedures etc for myself and my seasonal staff, interns etc it’ll take a ton of BS and stress off my plate by creating a check list for the job as well as for one of us to come in behind them and check that it was done right as well for spot checks on the work being done.

What you want doesn't exist anywhere, so you'll need to make it yourself.

One thought might be to have one person taking video of someone doing each process, then use the video as a reference for writing the cheat sheets.

Narrate what tools you're using, any oddities, safety warnings, etc. get some close-ups, and use screen captures to illustrate your printed instructions where needed. This could be a fairly efficient way to generate instruction sheets.

You could do much the same by taking lots of photos and notes of the process, but that could lead to missed steps and could take longer.


If a shop manual is available, that's a useful reference, but not enough. Shop manuals tend to be addressed to the experienced mechanic; they skip and gloss over a lot of things you should "just know", they use terminology your crew won't understand, and they hop around the manual in the most maddening way. Processes are scattered all across chapters, torque specs are usually hidden in a table at the end of the chapter, and as you've noted, fastener and tool sizes are never mentioned.


Sure, you could also make each process into a video, but that's a whole 'nuther ball of wax. Shooting and editing decent video takes an astonishing amount of time. Plus, you'd need some way for people to be able to view the video while they're doing the work. That might work if it's always in a shop where you might have wifi, but it sounds like some things happen out in the field.

 

[KnurledNut]

I have to depend on student interns, volunteers and seasonal staff for my workforce. And my toddler is more competent than my maintenance guy, so I’m generating these sheets to CYA as well as generate a paper trail. Government work is its own challenge sometimes.

Can you eliminate this system and hire a seasoned tech, even if its just a part-time position?
Sounds like this is a taxpayer funded government fleet. Seems odd to have such a dysfunctional system.

 

[subroc]

Without knowing who was hired to do what and at least some clearer idea of how big this fleet is an what sorts of vehicles are in it, it is hard to say what you could or should do. What are the interns actually there for? Why are they there what are yhey there to learn? The maintenance guy, is he building maintenance, all around maintenance or something else and is this fleet his stuff or someone elses? Is this government? Exactly what's the goverments link here? What are the tractors used for?

Anyway, if you are not a technical writer or were not tasked to do such a thing be careful. Make sure you know all the requirements before you task someone, especially an intern, to meet them.