Are linkage pins hardened?

[Matt_Meiser]

I'm in the process of converting my rotary cutter to work with my iMatch. I'm basically working from a set of pictures I took of an LX4 cutter at the deere dealer and am close to being done. However, I need to add two pins in the linkage. I made the diameter of the holes for these pins 3/4" to match the top link pins on my implements, but they are going to have to be longer than what I think I'll be able to buy so I was thinking of buying some 3/4" rod and making my own pins. I'm wondering if that will work or if I need something harder than mild steel (like tool steel that has been through the heat-quench-temper process?)

[Soundguy]

Lift and link pins are usually hard.

Soundguy

[blacksmith]

If you can get grade 5 or better grade 8 bolts, that is the way to go. They ar made from a alloy steel stronger than regular steel.

[Matt_Meiser]

Thanks! I think TSC sells grade 8 in 3/4" so I'll check them out at lunch.

[DieselPower]

Don't forget to grab some locknuts while your there. Since the bolt may have a tendancy to spin it will keep your nuts from falling off.

[Matt_Meiser]

keep your nuts from falling off.

That would be bad.

[shaley]

A 3/4" pin made from mild steel (A36) will hold 10,000 lbs in single shear. The top link pin is in double shear so it should hold 20,000 lbs before failure. How much do you think your force will be on this pin? It's not clear in your post as to weather the pin is in shear or bending.

[Soundguy]

I wouldn't monkey around with mild steel hardware anywhere on a tractor lift that supports weight. For the few extra pennies to get gr5 or gr8.. why not have that extra margin.

Soundguy

[Matt_Meiser]

These pins are in shear. I actually found long enough pins at TSC, then came home and figured out if I rearranged the stack-up of the components I could use regular length ones anyway so I was back at TSC today. I'm hoping to finish up the engineering and fit-up tonight.