Head Bolts vs Grade 8's - Ford Truck Enthusiasts Forums

Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Head Bolts vs Grade 8's

 
  #1  
Old 11-29-2010, 01:22 PM
2ktrott
2ktrott is offline
Freshman User
Thread Starter
Join Date: Jun 2007
Posts: 29
2ktrott is starting off with a positive reputation.
Head Bolts vs Grade 8's

I am replaceing the rusted out heads on my 460 F350. Do I need to use heads bolts or can I replace the exterior ones with Grade 8 bolts instead. Since I only need the exterior ones, can't see spending the $$ for a new set if I don't need to.
 
  #2  
Old 11-29-2010, 01:32 PM
L. Ward's Avatar
L. Ward
L. Ward is offline
Elder User
Join Date: Nov 2010
Location: Graniteville
Posts: 957
L. Ward has a good reputation on FTE.L. Ward has a good reputation on FTE.
If you need to replace some of them, you need to replace all of them, and no I would not use G8 hardware store bolts.
 
  #3  
Old 11-29-2010, 01:36 PM
2ktrott
2ktrott is offline
Freshman User
Thread Starter
Join Date: Jun 2007
Posts: 29
2ktrott is starting off with a positive reputation.
That's what I was afraid of. I will order a new set today. Thanks
 
  #4  
Old 11-29-2010, 02:34 PM
bubblegum's Avatar
bubblegum
bubblegum is offline
Senior User
Join Date: Nov 2010
Location: in the shadows
Posts: 273
bubblegum is starting off with a positive reputation.
What about stronger bolts (Grade-10?) from a specialized place like Fastenal or McMaster-Carr?
 
  #5  
Old 11-29-2010, 06:23 PM
Ohio Ford Farm's Avatar
Ohio Ford Farm
Ohio Ford Farm is offline
Elder User
Join Date: Feb 2007
Location: Madison Ohio
Posts: 690
Ohio Ford Farm is gaining momentum as a positive member of FTE.Ohio Ford Farm is gaining momentum as a positive member of FTE.
Originally Posted by bubblegum View Post
What about stronger bolts (Grade-10?) from a specialized place like Fastenal or McMaster-Carr?
Problem .. well use to be was Head bolts were a odd length. G10 might work but you might have a hard time finding that size in the length you need. Longer one just don't fit. Fastenal is a LOT of import stuff. McMaster - Carr is a great place but they take to much of my money every year! LOL I think you woudl still be better off just getting a set and know there the right grade and size to do the job.

Just looked Only thing McMaster has in the Grade 10.9 with the flange head is metric. That kind of sucks! I need to complain to them! LOL
 
  #6  
Old 11-29-2010, 06:37 PM
danr1
danr1 is offline
Post Fiend
Join Date: Aug 2006
Location: Sand Lake, MI
Posts: 5,640
danr1 has a great reputation on FTE.danr1 has a great reputation on FTE.danr1 has a great reputation on FTE.danr1 has a great reputation on FTE.danr1 has a great reputation on FTE.
Yea I agree and while I'm all for saving a few bucks/short cuts whenever possible, and even though they might work just fine I wouldn't use the grade 8's, replace all the bolts with "stock" head bolts.

You don't want to have to pull the head/s again because the bolts exact makeup wasn't right, might not withstand the temperature swings long term for example.
 
  #7  
Old 11-29-2010, 07:32 PM
EPNCSU2006's Avatar
EPNCSU2006
EPNCSU2006 is offline
Post Fiend
Join Date: Nov 2002
Location: Concord, NC
Posts: 9,436
EPNCSU2006 has a great reputation on FTE.EPNCSU2006 has a great reputation on FTE.EPNCSU2006 has a great reputation on FTE.EPNCSU2006 has a great reputation on FTE.
Just looked Only thing McMaster has in the Grade 10.9 with the flange head is metric. That kind of sucks! I need to complain to them! LOL
Class 10.9 is a metric specification, roughly equivalent in strength to SAE grade 8. That's why you can't find standard size fasteners with a class 10.9 strength rating.

As for the head bolts, I would try ARP if you don't want factory replacements. You can probably find replacements at say NAPA or CarQuest. I think if you're going to replace any of them that you should go ahead and replace them all.
 
  #8  
Old 11-29-2010, 07:49 PM
91chevywt's Avatar
91chevywt
91chevywt is offline
Senior User
Join Date: Sep 2010
Posts: 363
91chevywt is gaining momentum as a positive member of FTE.
I always get a new set of head bolts for a major overhaul or a head gasket job. Not a place to go cheap. If you want better than stock bolts, or would rather have studs then ARP should make something for you
 
  #9  
Old 11-29-2010, 07:51 PM
bubblegum's Avatar
bubblegum
bubblegum is offline
Senior User
Join Date: Nov 2010
Location: in the shadows
Posts: 273
bubblegum is starting off with a positive reputation.
Originally Posted by Ohio Ford Farm View Post
Problem .. well use to be was Head bolts were a odd length. G10 might work but you might have a hard time finding that size in the length you need. Longer one just don't fit. Fastenal is a LOT of import stuff. McMaster - Carr is a great place but they take to much of my money every year! LOL I think you woudl still be better off just getting a set and know there the right grade and size to do the job.
It was just a random idea, nothing more, but thanks for the explanation of why it was a bad idea

Originally Posted by EPNCSU2006 View Post
Class 10.9 is a metric specification, roughly equivalent in strength to SAE grade 8. That's why you can't find standard size fasteners with a class 10.9 strength rating.
I have seen metric bolts that have 12.9 written on their head, would those be roughly equivalent in strength to Grade-10 standard bolts? (this is just for my own general knowledge)
 
  #10  
Old 11-29-2010, 07:59 PM
L. Ward's Avatar
L. Ward
L. Ward is offline
Elder User
Join Date: Nov 2010
Location: Graniteville
Posts: 957
L. Ward has a good reputation on FTE.L. Ward has a good reputation on FTE.
The first number is the tensile strength or the pressure required to actually break the bolt.. This number can be between 4 and 14 with 14 being the toughest. To convert that number into something useful, take the first number on the head, multiply it by 100 (this give you tensile strength in N/mm2), then multiply it by 145 to get you the PSI that the bolt is rated at. A metric bolt with a 12 for the first digit, for example, would have a tensile strength of 174,000 PSI (12x100=1,200N/mm2 x 145=174,000psi).

Bolt Grade Markings and Strength Chart

<table style="width: 447pt; margin-left: 3.75pt;" border="1" cellpadding="0" cellspacing="0" width="596"><tbody><tr style="height: 24pt;"> <td rowspan="2" style="width: 16%; height: 24pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Head Markings

</td> <td rowspan="2" style="width: 13%; height: 24pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Grade or Class

</td> <td rowspan="2" style="width: 15%; height: 24pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Material

</td> <td rowspan="2" style="width: 15%; height: 24pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Nominal Size Range
(Inches)

</td> <td colspan="3" style="height: 24pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Mechanical Properties

</td> </tr> <tr> <td style="width: 11%; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Proof Load (psi)

</td> <td style="width: 13%; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Minimum Yield Strength (psi)

</td> <td style="width: 13%; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Minimum Tensile Strength (psi)

</td> </tr> <tr> <td colspan="7" style="padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
American Bolts

</td> </tr> <tr style="height: 44.25pt;"> <td rowspan="2" style="padding: 0.25pt; height: 44.25pt;" valign="top">

No Markings

</td> <td rowspan="2" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Grade 2

</td> <td rowspan="2" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Low or Medium Carbon Steel

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
1/4 thru 3/4

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
55,000

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
57,000

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
74,000

</td> </tr> <tr style="height: 45pt;"> <td style="padding: 0.25pt; height: 45pt;" valign="top">
Over 3/4 thru 1-1/2

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
33,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
36,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
60,000

</td> </tr> <tr style="height: 45pt;"> <td rowspan="2" style="padding: 0.25pt; height: 45pt;" valign="top">

3 Radial Lines

</td> <td rowspan="2" style="padding: 0.25pt; height: 45pt;" valign="top">
Grade 5

</td> <td rowspan="2" style="padding: 0.25pt; height: 45pt;" valign="top">
Medium Carbon Steel, Quenched and Tempered

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
1/4 thru 1

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
85,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
92,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
120,000

</td> </tr> <tr style="height: 45pt;"> <td style="padding: 0.25pt; height: 45pt;" valign="top">
Over 1 thru 1-1/2

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
74,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
81,000

</td> <td style="padding: 0.25pt; height: 45pt;" valign="top">
105,000

</td> </tr> <tr style="height: 1.25in;"> <td style="padding: 0.25pt; height: 1.25in;" valign="top">

6 Radial Lines

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Grade 8

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Medium Carbon Alloy Steel, Quenched and Tempered

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
1/4 thru 1-1/2

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
120,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
130,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
150,000

</td> </tr> <tr style="height: 44.25pt;"> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Stainless markings vary. Most stainless is non-magnetic

</td> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
18-8 Stainless

</td> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Steel alloy with 17-19% Chromium and 8-13% Nickel

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
1/4 thru 5/8

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
40,000 Min. 80,000 90,000 Typical

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
100,000 125,000 Typical

</td> </tr> <tr style="height: 24pt;"> <td style="padding: 0.25pt; height: 24pt;" valign="top">
3/4 thru 1

</td> <td style="padding: 0.25pt; height: 24pt;" valign="top">
</td> <td rowspan="2" style="padding: 0.25pt; height: 24pt;" valign="top">
40,000 Min. 45,000 70,000 Typical

</td> <td style="padding: 0.25pt; height: 24pt;" valign="top">
100,000 Typical

</td> </tr> <tr style="height: 30pt;"> <td style="padding: 0.25pt; height: 30pt;" valign="top">
Above 1

</td> <td style="padding: 0.25pt; height: 30pt;" valign="top">
</td> <td style="padding: 0.25pt; height: 30pt;" valign="top">
80,000 90,000 Typical

</td> </tr> <tr style="height: 19.5pt;"> <td colspan="7" style="height: 19.5pt; padding: 0.25pt; background: none repeat scroll 0% 0% rgb(217, 217, 217);">
Metric Bolts

</td> </tr> <tr style="height: 1.25in;"> <td style="padding: 0.25pt; height: 1.25in;" valign="top">

8.8

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Class 8.8

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Medium Carbon Steel, Quenched and Tempered

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
All Sizes thru 1-1/2

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
85,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
92,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
120,000

</td> </tr> <tr style="height: 1.25in;"> <td style="padding: 0.25pt; height: 1.25in;" valign="top">

10.9

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Class 10.9

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
Alloy Steel, Quenched and Tempered

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
All Sizes thru 1-1/2

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
120,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
130,000

</td> <td style="padding: 0.25pt; height: 1.25in;" valign="top">
150,000

</td> </tr> <tr style="height: 44.25pt;"> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Stainless markings vary. Most stainless is non-magnetic

</td> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
A-2 Stainless

</td> <td rowspan="3" style="padding: 0.25pt; height: 44.25pt;" valign="top">
Steel alloy with 17-19% Chromium and 8-13% Nickel

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
1/4 thru 5/8

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
40,000 Min. 80,000 90,000 Typical

</td> <td style="padding: 0.25pt; height: 44.25pt;" valign="top">
100,000 125,000 Typical

</td> </tr> <tr style="height: 24pt;"> <td style="padding: 0.25pt; height: 24pt;" valign="top">
3/4 thru 1

</td> <td style="padding: 0.25pt; height: 24pt;" valign="top">
</td> <td rowspan="2" style="padding: 0.25pt; height: 24pt;" valign="top">
40,000 Min. 45,000 70,000 Typical

</td> <td style="padding: 0.25pt; height: 24pt;" valign="top">
100,000 Typical

</td> </tr> <tr style="height: 30pt;"> <td style="padding: 0.25pt; height: 30pt;" valign="top">
Above 1

</td> <td style="padding: 0.25pt; height: 30pt;" valign="top">
</td> <td style="padding: 0.25pt; height: 30pt;" valign="top">
80,000 90,000 Typical

</td> </tr> <tr style="height: 0.5in;"> <td colspan="7" style="padding: 0.25pt; height: 0.5in;" valign="top"> Tensile Strength: The maximum load in tension (pulling apart) which a material can withstand before breaking or fracturing.
Yield Strength: The maximum load at which a material exhibits a specific permanent deformation
Proof Load: An axial tensile load which the product must withstand without evidence of any permanent set.

</td></tr></tbody></table>
 
  #11  
Old 09-10-2013, 10:07 AM
warren561
warren561 is offline
Senior User
Join Date: Dec 2012
Location: 01867
Posts: 346
warren561 is starting off with a positive reputation.
Originally Posted by L. Ward View Post
The first number is the tensile strength or the pressure required to actually break the bolt.. This number can be between 4 and 14 with 14 being the toughest. To convert that number into something useful, take the first number on the head, multiply it by 100 (this give you tensile strength in N/mm2), then multiply it by 145 to get you the PSI that the bolt is rated at. A metric bolt with a 12 for the first digit, for example, would have a tensile strength of 174,000 PSI (12x100=1,200N/mm2 x 145=174,000psi).

Bolt Grade Markings and Strength Chart
Sorry to dig up such an old thread. But this chart is so handy!
 
  #12  
Old 09-11-2013, 11:55 PM
quaddriver
quaddriver is offline
Posting Guru
Join Date: Jan 2004
Location: Cook Forest and Irwin PA
Posts: 2,467
quaddriver has a great reputation on FTE.quaddriver has a great reputation on FTE.quaddriver has a great reputation on FTE.quaddriver has a great reputation on FTE.
unless you are using ttys (torque to yeild bolts) which you aint, you can re-use a head bolt set from about any street 460.

that being said, dont pop off the bottoms and not the top, you will blow the head gasket shortly thereafter....do it right or not at all (also head bolts tend to be shouldered to minimize movement
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jeff Metz Jr.
1987 - 1996 F150 & Larger F-Series Trucks
5
04-27-2017 05:05 PM
mr lucky
1987 - 1996 F150 & Larger F-Series Trucks
4
03-10-2017 02:03 PM
Jimmiej08
1948 - 1956 F1, F100 & Larger F-Series Trucks
7
02-15-2017 01:38 PM
frdf250
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
7
05-09-2016 11:34 AM
countryartistjk
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
3
01-14-2012 01:09 PM


Thread Tools
Search this Thread
Quick Reply: Head Bolts vs Grade 8's


Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.