Shear Pin Size and maintenance

Can anyone tell me what the correct shear pin size is for a 520.

I have put in cotter pins in the past when I do shear one but I was wondering what the exact size should be.

Further this will be my 3rd full season running. I take summers off. usually run into the end of May and start back in the fall. I clean the tubes and ash out as well as scrape the sides of the firebox. I run a light all summer long inside to reduce any condensation or moisture some.

My question is. Being this is the 3rd year without any major teardown. Is it time that the screws come out and the pot comes out for any maintenance? Grate replacement?

Any recommendations greatly appreciated.

Thanks

Shouldn't use cotter pins, they probably won't break. Not sure if this offer is still good:

Special shear pin offer to the coal forum

stoker-man wrote:Instead of using nails, brass rods, etc, anybody wanting genuine shear pins for their efm stoker can send a check for $5.00 made out to: efm Sales Co., 302 S. 4th St., Emmaus, PA 18049 and we'll send you 12 shear pins by return mail.

Otherwise uou can get the pins from EFM dealer. I believe it's just a brass welding rod they cut them from, you can get them for a few bucks from welding shop.

Mine have broken...

about 1 or 2 a year it seems...

But I would like to use the correct items... Thanks.

Mark, do you know what causes the shear pins to break? Oversize coal? Worn parts?

The cotter pins or shear pins broke? I'd imagine the cotter pins don't fit properly so you basically have a shearing action every start because of the play eventually cutting it. None the less steel is not what you want to use here because if it doesn't break you're going to break some very expensive parts. It's good enough for emergency uses but you can bet I'd be right on getting the right pin.


If it's the standard pin breaking 1 or 2 a year is excessive, in 30 years with the Van Wert I think we broke 2 or 3. Each time there was a reason for it breaking.

That address is no longer valid, as efm has moved out of there. I'll contact Mark.

The shear pins are 1/8" X 1 1/4" and are rated to break at 25 ft. lbs. You should try to determine the cause if they are breaking frequently.

Alot of guys I talk to seen to think that the cotter pins that hold the auger to the clutch mechanism are the "shear pins". They are surprised when they find out that the shear pin is on the outside of the clutch mechanism by the square end.

Mark (PA) wrote:Can anyone tell me what the correct shear pin size is for a 520.

I have put in cotter pins in the past when I do shear one but I was wondering what the exact size should be.

Further this will be my 3rd full season running. I take summers off. usually run into the end of May and start back in the fall. I clean the tubes and ash out as well as scrape the sides of the firebox. I run a light all summer long inside to reduce any condensation or moisture some.

My question is. Being this is the 3rd year without any major teardown. Is it time that the screws come out and the pot comes out for any maintenance? Grate replacement?

Any recommendations greatly appreciated.

Thanks

Just call the shop were you bought the boiler the pins will be sent to you . But you do need to find out what is the cause that
is breaking them I been running mine 3 years with the same pin & I use buck never broke one somthing is not right should
not break them like that unless you burning rock in it or a lot of dirt /fines in the coal