The lead machinist in the shop at work measured the AC Delco replacement I ordered from Rock Auto. He said it is an M11-1.5 pitch bolt. So it is metric with a 3/8" hex head on it. Go figure.

 

My memory was actually correct! M11x1.5 is an odd duck. Except for M3 and M5, metric tends to avoid odd numbers going M6, 8, 10, 12, 14 etc

 

Wow! That is odd...

I'm in need of an odd M11-1.25 grade 5 or grade 8 bolt about 100MM long fully threaded. Anyone know where I can find one reasonably? If not, I may have to re-thread the piece to take a 7/16" fine threaded bolt..

 

There used to be a fastenall store here..... but, they seem to have dried up and blew away. They had a HUGE selection of nuts/bolts/fasteners of all descriptions.

 

We have one in this area, but that bolt thread size and pitch is so odd, I'm scared to see how badly they may pucker me up for it, if I can even find it at all. In checking online, I only found it via a China outlet with a LONG lead time for delivery, since it was so odd...

 

Grade X is for standard, Metric uses 4.8,8.8,10.9 and 12.9 which is stronger than a grade 8.


I usually check McMasterCarr for hardware but they don't even have any listing for M11. You may want to see what heli coil you can use for something more standard if going up in size is not an option.

 

Going up in size is an option because that's all the Dorman "repair" bolts do. Presumably M12 but I don't remember

 

I come up with 1.25 being 20.3 TPI. So yeah, have you tried a 7/16 fine thread? I wonder if you could get away with a chaser and just shove those threads around a tiny bit?

If it's not super critical get a 7/16" fine thread tap bolt (=fully threaded) and run an M11x1.25 die over it. The die would also be special order

 

Also thank you, your mention of M11x1.25 prompted me to order a Chinesium tap and die from ebay for $13. "Just in case" -- which ensures I'll never need it as long as I have it.

One of the best things I did years ago was order the relatively odd die for the front stub axles and that has proved useful. I think it was 1-1/8" - 27 maybe?

 

If anyone needing wierd bolt sizes, just regular sizes, shoulder bolts, look at McMaster-Carr, I used them for a lot of my orders for shipboard defence systems. No, you don't need a large order, only 1 thing is ok. They have a plethora of items.