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OT -Snowblower shear pins

Old Bill

Hot Rolled
Joined
Apr 3, 2006
Location
San Antonio, TX
Old Bill finally bought a snowblower. It came with extra shear pins.(actually steel 1/4-20 bolts).I wanted to buy some more spares but they were out of stock. I could easily make some but I was concerned about using too strong of a material and NOT failing when they should.Hex head bolts or cap screws have marks on the head indicating their strength. I thought of using brass as it should fail before steel. My wife is worried that I do the right thing as I told her this is her Mothers Day gift.
Old Bill
 

flutedchamber

Hot Rolled
Joined
May 31, 2009
Location
Mays Landing, New Joisey
Old Bill finally bought a snowblower. It came with extra shear pins.(actually steel 1/4-20 bolts).I wanted to buy some more spares but they were out of stock. I could easily make some but I was concerned about using too strong of a material and NOT failing when they should.Hex head bolts or cap screws have marks on the head indicating their strength. I thought of using brass as it should fail before steel. My wife is worried that I do the right thing as I told her this is her Mothers Day gift.
Old Bill

I have an old Craftsman snow blower from '69. It uses a 5/16 shear bolt. When I could no longer find the shear bolts for the unit I used a standard grade 2 bolt in it's place. The grade 2 bolt seems to hold up as well as the shear bolt did. I usually go thru one shear bolt about every 5 years.

If you were worried that the grade 2 bolt would be too strong, you could thru drill the bolt with a 1/16 bit to reduce it's cross section.
 

shapeaholic

Stainless
Joined
Oct 14, 2003
Location
Kemptville Ontario, Canada
Cheap bolts

Do yourself a favour, buy the cheapest hardware store bolts you can find. They may shear sooner than the "OEM" shear pins, but "bolts is cheap, augers and shafts ain't"

If you are concerned that the cheap bolts may smear, you can cut shallow grooves in the bolts where they would line up with the auger shaft.

That's how we do it here in " the Great White North"

Cheers
Pete
 

Ranchero50

Cast Iron
Joined
Jan 2, 2008
Location
Hagerstown MD, USA
Ditto that, 1.5" grade 2's from Tractor Supply and some nylock nuts. Handfull of each and two 7/16" wrenches in the coverall pockets. Accidently put a grade 5 in before the first big snow this year, blew the auger gearbox apart. Mocked it up and spool gunned it back together.:nutter:

Still going... The gearbox replacement was around $150 with a three week wait, 8hp 24" cut craftsman

Jamie
 

agertool

Aluminum
Joined
Mar 14, 2005
Location
Waterford
I would not go with brass, you might not get too much done before they break. If you can identify what grade bolt it is, get the same. If you are concerned about it not breaking soon enough, when you turn the grooves in the shear bolt for a break location, turn them a little deeper than the factory one, say .005 or even .010.

Definitely do not go a grade above for reasons mentioned by Ranchero50. Make some more up than you need and carry them with you so when they break you can change right on the spot. I have had to change my fair share this year already. With the 20"+ snow we got since Friday my tractor and blower have got a real work out
 

L Vanice

Diamond
Joined
Feb 8, 2006
Location
Fort Wayne, IN
I broke one last month when I hit a big snow-covered rock along the edge of my neighbor's driveway. I made a temporary substitute from a plain head (the cheap low grade kind) bolt by turning grooves a bit deeper than the ones in the original bolt. Then I went to a local garden store to buy real ones. They wanted $1.50 each, but did not have any of the correct size in stock. I called the local Sears store, but they were out also. Then I went to Sears.com and found them for $3.49 per package of four bolts and nuts. I ordered two sets and they came in two days, well before I needed to use the snowblower.

http://www.sears.com/shc/s/p_10153_12605_07188289000P?keyword=07188289000&sLevel=0

Larry
 

Conrad Hoffman

Titanium
Joined
May 10, 2009
Location
Canandaigua, NY, USA
I went through dozens of expensive commercial "shear pins" on my Frontier blower for no good reason. My theory is that the dead-man safety system engages the auger very suddenly, causing what appear to be fully threaded #2 bolts to eventually fail. Usually sooner rather than later. I was really afraid to use anything different, but became more afraid that I'd freeze to death changing shear pins, or have a heart attack from getting so pissed off at the thing. I finally started using cheap bolts and nyloc nuts, but went to bolts that are *not* fully threaded. The full 1/4" shank has to shear. This has worked fine, shearing when it sucks up a rock or piece of firewood, but not for no good reason.

Best,
Conrad
 

Ghost

Cast Iron
Joined
Aug 27, 2009
Location
Royersford PA USA
Just so you know, the local John Deere dealer does not sell sear bolts. They sell cheap grade 2 bolts labeled as shear bolts. My dad drives a roll back for them and has been told to stop and pick more up from the hardware store.
 

CalG

Diamond
Joined
Dec 30, 2008
Location
Vt USA
I have a box of 1/4 -20 X 2 inch hardware store hex heads along with a box of nuts.
The garden tractor is a bit powerful for this 42" single stage blower, and the thing shears bolts like crazy with this soggy snow we have had.

After the sheared bolt is driven out, and a new one tapped in, I finger tighten a common nut and give the exposed threads a pop with the hammer to distort things.
 

Winfield

Hot Rolled
Joined
Dec 7, 2003
Location
Running Springs, Ca USA
I make shear pins using cheap hardware store 1/4-20 bolts and machining two grooves that match the original shear pin design. The bolts are held on with a Nylock nut. Works pretty well as the stupid design of my Troy-bilt snowthrower has six shear pins on six separate auger blades. PITA to replace. A single rock can knock out three shear pins at a time. One has to knock the remaining piece of shear pin out with a punch. I made a batch of 20 a few weeks ago and have already gone through 10 of them. Yeah it does snow in Southern California at 6K ft. elevation. The heated hand grips sure help after getting your hands cold replacing shear pins.
 








 
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