Bolt size

[Brady D]

I’ve been trying to find a replacement for this bolt for the front axle of my tractor it’s an m18 bolt however I cannot find one with threads as fine

 

[Mendonsy]

Try McMaster-Carr. They carry a lot of metric fasteners.

 

[NoTrespassing]

I’ve been trying to find a replacement for this bolt for the front axle of my tractor it’s an m18 bolt however I cannot find one with threads as fine
View attachment 819753

Either buy a cheap thread gage or hold a ruler next to the bolt and take another picture so we can guess the pitch

 

[MH8675309]

Might have to get it from a dealer. Last time I needed one like this it was $120 from the JD dealer

 

[Eagle1]

Guessing M18x1.5 Fine Thread
Hex Bolts 10.9 M18X1.5 Extra Fine DIN 960/961

They do make M18x1.0 super fine thread

or the more common
M18x 2.0

 

[MountainBuck]

Might have to get it from a dealer. Last time I needed one like this it was $120 from the JD dealer

Yikes! For $120, I think I'd file new flats and clean this bolt up.

 

[oldnslo]

M18 x 1.0 is fine thread and would have approx 25 threads per inch be similar thread pitch to 3/8 - 24 UNF.

M18 x 1.5 would have approx 17 threads per inch and be similar thread pitch to 3/8 - 16 UNC

 

[Topzide]

Invest in a thread chaser kit along with thread gauges for standard and metric. That way you'll know what it is and be able to fix damaged threads! For that price you could get all 4 items and probably have some change leftover!

 

[WinterDeere]

OP hasn't been back, but if he is, here's a quick cheap job that will do what the amateur needs:

Amazon.com

There are much better and more complete thread gauges out there, but for someone just looking to match the odd bolt, this'll git'r done for under $10.

 

[ruffdog]

By measuring off the screen, it looks to be a 18x1.5 thread and is about 70mm long.