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? Learning resource for nuts and bolts.?

alwaysFlOoReD

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Sep 24, 2013
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Location
Airdrie, Alberta, Canada
I know about how to tell the difference between grade 2, 5, 8, and 12 bolts. But today I was sorting a pail of nuts by size and started wondering how they are marked or classified. I assume the gold colored ones are grade 8 but then I've seen gold colored bolts that were definitely not grade 8. Then there are the 3 side pinched nut, the integral washer that spins, the flanged nut, and several others. Same with washers.
So where can I go to learn?
 
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matt_i

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Mar 14, 2008
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SE Michigan
In broad generalities:

Grade 2 has no markings on the hex

Grade 5 has 3 hash marks on the hex

Grade 8 has 6 hash marks on the hex

Metric is typically marked with a number eg 8.8 or 12.9.

Socket head screws typically don't have a mark. But they seem to be a Grade 5 or better.

Beware of the trap that a Stainless Steel fastener is stronger. It is not. It is just more corrosion resistant in two steps, either 18-8/304 or the 316 metallurgies. In general 316ss is recommended for continuous immersion/below waterline or saltwater apps.

Lastly the coatings don't mean anything as far as the grade of fastener.
 

sberry

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Jun 18, 2005
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Brethren, Michigan
One of the reasons I like the tech manual is that there is a lot to it that is evidently missed in mechanic education. I didn't have it in college automotive. It took a long time for some of these basics to become reactionary so to speak.
 

Alexander

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May 24, 2014
Messages
169
Location
Hudson Valley, New York
Sometimes I like to just play around on McMaster's website, looking at stuff, finding hardware, tools, and materials I never knew existed. They usually give a brief description for each item, and what it's used for.

It's by far the most convenient and easily navigable website I've ever found.
 

brownbagg

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Joined
Mar 20, 2006
Messages
5,208
best book i ever had on bolts was an military aviation maintenance book
 

6PTsocket

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Mar 12, 2014
Messages
4,593
In broad generalities:

Grade 2 has no markings on the hex

Grade 5 has 3 hash marks on the hex

Grade 8 has 6 hash marks on the hex

Metric is typically marked with a number eg 8.8 or 12.9.

Socket head screws typically don't have a mark. But they seem to be a Grade 5 or better.

Beware of the trap that a Stainless Steel fastener is stronger. It is not. It is just more corrosion resistant in two steps, either 18-8/304 or the 316 metallurgies. In general 316ss is recommended for continuous immersion/below waterline or saltwater apps.

Lastly the coatings don't mean anything as far as the grade of fastener.
Just add 2 to the number of hash marks for the grade. Some of your missing grades also do exist. It is good to know how how metric relates to SAE. Metric are called class, not grade. Class 8.8 is roughly grade 5 and 10.9 is roughly grade 8. The numbers like 10.9 are not actually a decimal. The 10 and the 9 are for two different specs and they use the decimal to separate them. SAE stainless has it's own marking system. You might see an A followed by a number. Stainless is usually around grade 2. True, the plating does not affect the grade but grade 8 are often yellow zinc plated. I see where he got that idea.

Sent from my SM-G900V using Tapatalk
 

sberry

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The tractor store used to have 5 in gold, now they are green and the few 8 they have are blue. When I had other men and got a real deal on bolts only stocked 5. It cost a little more but they didn't replace with wrong bolt by accident.
Now I stock and collect some 2 and carry 5 also. It's a little incentive to replace more when it's cheaper where it can.
I spray about every nut I install, if it isn't smooth and can't be threaded on with fingers it gets tossed if it's in small sizes and common.
 
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Lelandwelds

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Sep 6, 2017
Messages
2,443
Location
Central Texas
Carr Lane, McMaster-Carr, aircraft vendors, vendors based in the shadow of John Deere or Manitowoc or Haas. Retired machinists or mechanical engineers or what have you are good sources .

The hard part is learning what you don't know. I miss the days of old farts hanging out at the pharmacy'S lunch counter or playing Dominos at the local hardware store. Mine had a retired millwright, a machinist who worked on the Hiroshima and Nagasaki bombs, and a guy who built steam engines. They always knew where to go. Hard part was escaping once you had an answer.
 

Schurkey

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Joined
Oct 27, 2011
Messages
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Location
The Seasonally Frozen Wastelands
Carroll Smith's "Nuts, Bolts, Fasteners, and Plumbing" is THE best single book on the subject.
https://www.amazon.com/dp/0879384069/?tag=atomicindus08-20

Beyond that, there are multiple other books that are good and that I can recommend with a clear conscience...but the Carroll Smith books are the cream of the crop. The last I looked--and it's been a year or more--the family of Carroll Smith (RIP) had a web site where they were selling his books.

Aww, heck. Here's the web site: http://www.carrollsmith.com/books/ A hundred fifteen dollars gets you everything that's available...and VERY WELL WORTH IT.



Mike Mavrigian, High Performance Fasteners and Plumbing
https://www.amazon.com/dp/1557885230/?tag=atomicindus08-20

Forbes Aird, High Performance Hardware
https://www.amazon.com/dp/1557883041/?tag=atomicindus08-20

Timothy Remus, Hot Rod Hardware
https://www.amazon.com/dp/1929133014/?tag=atomicindus08-20

I am not sure how to get it but John Deere has a book for tech students just for this.
John Deere, Fasteners Principles of Service
https://www.amazon.com/dp/0866913491/?tag=atomicindus08-20

I own and have read each of these books. They're ALL "recommended"...buy the Carroll Smith book(s), get the others from the library. For the record, I appreciated the John Deere book the least. I'm not saying it's "bad", but it's not oriented to automotive performance.


Oh, yeah. Another edit. BEWARE of Grade 8.2 bolts. I was forced to learn about that mess from an eBay seller that was bragging them up. The heat-treat is different (lower temperature) than "real" Grade 8. If they're used in a high-temperature situation, they can fail. The eBay seller's bolts also had full-diameter shanks when reduced-diameter is useful on short bolts to promote stretch. Junk.
 
Last edited:

lakelandcat

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Joined
Sep 25, 2017
Messages
7,327
In broad generalities:

Grade 2 has no markings on the hex

Grade 5 has 3 hash marks on the hex

Grade 8 has 6 hash marks on the hex

Metric is typically marked with a number eg 8.8 or 12.9.

Socket head screws typically don't have a mark. But they seem to be a Grade 5 or better.

Beware of the trap that a Stainless Steel fastener is stronger. It is not. It is just more corrosion resistant in two steps, either 18-8/304 or the 316 metallurgies. In general 316ss is recommended for continuous immersion/below waterline or saltwater apps.

Lastly the coatings don't mean anything as far as the grade of fastener.
:thumbup: Don't forget a galvanized bolt and nut are a dull silver, never try to tack weld them they will put off a bad gas.
 

L5wolvesf

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Joined
Dec 4, 2011
Messages
1,831
Location
Northern AZ
Carroll Smith's "Nuts, Bolts, Fasteners, and Plumbing" is THE best single book on the subject.
https://www.amazon.com/dp/0879384069/?tag=atomicindus08-20

Beyond that, there are multiple other books that are good and that I can recommend with a clear conscience...but the Carroll Smith books are the cream of the crop. The last I looked--and it's been a year or more--the family of Carroll Smith (RIP) had a web site where they were selling his books.

Aww, heck. Here's the web site: http://www.carrollsmith.com/books/ A hundred fifteen dollars gets you everything that's available...and VERY WELL WORTH IT.

Ditto on the "To Win" series :bowdown: But IMO "Nuts, Bolts, Fasteners . . . " should have followed suit and been named "Screw To Win".
 
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mikegt4

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Sep 12, 2005
Messages
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Location
sw ohio
The tractor store used to have 5 in gold, now they are green and the few 8 they have are blue. When I had other men and got a real deal on bolts only stocked 5. It cost a little more but they didn't replace with wrong bolt by accident.
Now I stock and collect some 2 and carry 5 also. It's a little incentive to replace more when it's cheaper where it can.
I spray about every nut I install, if it isn't smooth and can't be threaded on with fingers it gets tossed if it's in small sizes and common.

The green and blue are just a dye to identify which price per pound the cashier should charge you. It comes off readily which acetone and other solvents. Colors may vary by retailer.
 

TRWham

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Aug 11, 2017
Messages
1,961
Location
East Cobb County, Georgia
Ditto on the "To Win" series :bowdown: But IMO "Nuts, Bolts, Fasteners . . . " should have followed suit and been named "Screw To Win".

I have the original blue Prepare and red Tune I probably bought about 1980 when I was first working on race cars during engineering school. I did buy Engineer when it came out, but only recently acquired Drive and Nuts when someone gave me them when he was purging stuff prior to moving.
 
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sberry

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Jun 18, 2005
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Brethren, Michigan
Yes,I understand the dye, agreed with someone else that it didn't matter. I also agree there are better and more complete books than the John Deere. It is basic and focuses on fundamentals. It's not specialty auto racing. It would explain a class 8.2 metric isn't a grade 8.
What I like about it is a basic explanation about thread friction and torque.
 

bwringer

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Joined
Jan 1, 2013
Messages
10,271
Location
Indianapolis
One thing that trips up a lot of folks are the different strength rating systems for metric and inch size stuff. Make sure you understand the differences depending on what you do most often.

Plus, within metric you also need to bear in mind the differences between JIS (most Asian machinery) and DIN (Euro) or SAE (US) specs.

Almost everything I work on is Japanese motorcycles and cars, so these are the fasteners, taps, dies, etc. I keep on hand. They can be surprisingly hard to find in hardware stores.
 

MFolks

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Feb 3, 2013
Messages
1,045
Location
Springfield Mo.
If you use Stainless Steel nuts with Stainless Steel fasteners,to reduce the chance of "Galling"(sticking and damaging the threads) get some of the silver Anti-Seize at the auto parts store,a small tube will last a long time,apply with an acid brush,a little goes a long ways,I put the Anti-seize on new sparkplugs too.
 

tonyprovo723

Well-known member
Joined
Jul 2, 2016
Messages
150
Manufacturing company I worked at used to dip stainless hardware in buckets of floor wax. Not as good as Anti-Seize, but they let the fasteners drip dry in bulk and it is a lot cleaner.

Sent from my SM-G965U using The Garage Journal mobile app
 

Schurkey

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Joined
Oct 27, 2011
Messages
2,369
Location
The Seasonally Frozen Wastelands
Oh, yeah. Another edit. BEWARE of Grade 8.2 bolts. I was forced to learn about that mess from an eBay seller that was bragging them up. The heat-treat is different (lower temperature) than "real" Grade 8. If they're used in a high-temperature situation, they can fail. The eBay seller's bolts also had full-diameter shanks when reduced-diameter is useful on short bolts to promote stretch. Junk.
It would explain a class 8.2 metric isn't a grade 8.
You misunderstand. I'm warning people about SAE Grade 8.2. This is not a metric class, this is an inferior variation of SAE Grade 8. Six lines on the bolt head, but they're not evenly spaced around the head like a "real" Grade 8--they're all on one side.

http://engineershandbook.com/Tables/boltgrades.htm
 

metalmagpie

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Joined
Nov 1, 2011
Messages
798
Location
Seattle
School of hard knocks taught me pretty well. Start out taking apart your mom's steam iron and your dad's table radio when you're about six. Graduate to building soap box derby racers when you're nine or ten. Keep tinkering, collecting tools and generally monkeying around the rest of your life. By the time you're my (classified) age, you rarely have to measure a bolt any more. Even though I can't see squat up close, I can tell a no. 10 screw from a no. 8 at least nine times out of ten.

metalmagpie
 

HoosierBuddy

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Joined
May 9, 2006
Messages
2,922
Location
Southern Indiana
At 54 I'm still learning.

I'm in the midst of putting a new engine in my kid's Subaru. Of course the fastener's are metric pitch and diameter but they are "JIS"...which is Japanese Industrial Standard. The difference is the hex sizes are all off from standard metric. For example...all of the M8 Fasteners require a 12mm socket where a standard metric bolt would require 13 mm.

On the subie, basically 99% of the bolts require either a 10mm, 12mm or 14mm socket because it's all JIS spec.

Phil
 

justsam

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Joined
Aug 20, 2010
Messages
1,267
Location
Penngrove, California
I too became a huge fan of the Carrol Smith book on fasteners. It really did convince me of the importance of proper fasteners. Now I can't just buy "nuts and bolts", I have to specifically know the hardness, plating type, head shape and type, etc. Pretty much convinced me to toss out my "miscellaneous hardware" box, and projects now include specifying and obtaining proper fasteners.
 

sberry

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Messages
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Location
Brethren, Michigan
I aint that fussy but consciously use the correct thing. I try to be as common as I can. Use what they put in it from the factory.
 
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