Shear Bolts for IH (International McCormik) 47... Also Flat Belt Source?

[CliffordK]

I just got an IH (International McCormick) 47.

What size of shear bolts should it have?

Apparently there are 3 shear bolts.

1 on flywheel
1 on feed forks
1 on needle assembly.

I bought a bunch of 2", 5/16" bolts. Grade 3, 5, & 8.

I think it had a grade 8 bolt in the flywheel, and grade 5 bolts in the other locations. My thoughts would be to put in something fairly soft, and see how well they last.

It also has a 4" x 8'6" (102") flat drive belt. Anybody have a good source for flat drive belts?

Thanks,
Cliff

 

[CliffordK]

To reply to my question.
After asking the question, I found this sticker on the baler (IH 47).


3 dashes indicate a grade 5 bolt, per manufacture specs.

 

[coondle]

My advice is DO NOT PUT SOFT BOLTS IN
WHY?
The purpose of these bolts is to have a deliberate weak link thus protecting the machine from overload and breakages and thus your pocket
three mark grade 5 bolts are high tensile and are actually designed to be strong along their length ie tensile strength but at same time are hard
When used as shear bolts the characteristics of the metal are different
Soft bolts shear slowly such that the metal hangs on and more smears off making bolt hard to get out of hole as it tends to have a bend in direction of failure so drive continues even after overload first occurs = damage to machine
HT bolts because of hardness fail rapidly once failure is started hence shear off cleanly and easy to remove from hole
The manufacturer says GRade 5 for a reason USE THEM and nothing else
If failure is too regular look for the source of the overload
Good luck