Need Help ID this Nut & Bolt

   / Need Help ID this Nut & Bolt #1  

W8BYA

Silver Member
Joined
Dec 28, 2010
Messages
197
Location
Ossian, Indiana
Tractor
NH Boomer 40
Howdy group. I came across a very large number of these new nuts & bolts but am not familiar with the stamping on the head. I suspect they are metric as the bolt measures exactly 3 cm in length and a standard 5/16-18 coarse will almost thread on but does not. I read it as 3F on one side then 8.8 across from that. Looks like a heavy Chromate coating for corrosion resistance.
mystery-bolt.jpg
 
   / Need Help ID this Nut & Bolt #2  

ptsg

Elite Member
Joined
Apr 3, 2013
Messages
4,884
Location
Portugal
Tractor
Branson F36Rn
It's an M8x1.25 30 mm long bolt. The 8.8 is the grade for metric bolts.

In the land of metric, we don't even bother to mention the pitch (1.25 in this case), only if we actually want a fine thread or something. So we would just call it M8x30 mm bolt.

1652125928627.png
 
   / Need Help ID this Nut & Bolt #3  

JethroB

Veteran Member
Joined
May 19, 2020
Messages
1,725
Location
Really Deep Southeast
Tractor
Kubota L5460 HST Open Station, Kubota L5460 HST Cab, MF 135 Diesel
It's an M8x1.25 30 mm long bolt. The 8.8 is the grade for metric bolts.

In the land of metric, we don't even bother to mention the pitch (1.25 in this case), only if we actually want a fine thread or something. So we would just call it M8x30 mm bolt.

View attachment 745222
Ok, I understand the 8.8 grade part, but how did you know M8x30mm? From the markings?
 
   / Need Help ID this Nut & Bolt #4  

ptsg

Elite Member
Joined
Apr 3, 2013
Messages
4,884
Location
Portugal
Tractor
Branson F36Rn
Ok, I understand the 8.8 grade part, but how did you know M8x30mm? From the markings?
The thread diameter and pitch of the M8 and the 5/16 bolts or nuts are very close to each other. It will actually work if you force it there, but you may end up with a slight mix between a 5/16 and a M8 thread.

As far as the length, the provided metioned in the first post.
 
Last edited:
   / Need Help ID this Nut & Bolt
  • Thread Starter
#5  
OP
W8BYA

W8BYA

Silver Member
Joined
Dec 28, 2010
Messages
197
Location
Ossian, Indiana
Tractor
NH Boomer 40
It's an M8x1.25 30 mm long bolt. The 8.8 is the grade for metric bolts.

In the land of metric, we don't even bother to mention the pitch (1.25 in this case), only if we actually want a fine thread or something. So we would just call it M8x30 mm bolt.

View attachment 745222
Hey that's great, thank you. A boat load of grade-5 bolts I can live with. Am I close in assuming the 3F marking is for 3 cm? But what about the F marking?
 
   / Need Help ID this Nut & Bolt #6  

ptsg

Elite Member
Joined
Apr 3, 2013
Messages
4,884
Location
Portugal
Tractor
Branson F36Rn
Hey that's great, thank you. A boat load of grade-5 bolts I can live with. Am I close in assuming the 3F marking is for 3 cm? But what about the F marking?
That would be a manufacturers marking/ID, so not really important.
 
   / Need Help ID this Nut & Bolt
  • Thread Starter
#8  
OP
W8BYA

W8BYA

Silver Member
Joined
Dec 28, 2010
Messages
197
Location
Ossian, Indiana
Tractor
NH Boomer 40
3F is Fontana Luigi
Darn it ! I was hoping these bolts were Ferrari or maybe Lamborghini :)

Thank you for letting me know. Fascinating all that information can be easily put on the head of a bolt.
 
   / Need Help ID this Nut & Bolt #9  

Root Cause

Platinum Member
Joined
Jun 28, 2021
Messages
784
Location
North Carolina mountains
Tractor
Mahindra 2638
There are times when English and metric overlap. It can be dangerous.
There are lots of ways to size a bolt. At my Lowes or ACE hardware stores have these and you can buy them as well.

Keep something close by. It will save you time and money the first time you force a bolt only to find out it won't hold and the threads are stripped.

1652130913941.png


I have a set of these in my tool bag.
1652131036541.png
 
   / Need Help ID this Nut & Bolt
  • Thread Starter
#10  
OP
W8BYA

W8BYA

Silver Member
Joined
Dec 28, 2010
Messages
197
Location
Ossian, Indiana
Tractor
NH Boomer 40
There are times when English and metric overlap. It can be dangerous.
There are lots of ways to size a bolt. At my Lowes or ACE hardware stores have these and you can buy them as well.

Keep something close by. It will save you time and money the first time you force a bolt only to find out it won't hold and the threads are stripped.

View attachment 745226


I have a set of these in my tool bag.
View attachment 745227
Both of these are great ideas. Normally I would go to my local fastenal (which is just 5 min away) but they have closed there main door, open only for P/U's etc. What a shame as they are a wonderful source.
 
 
Top