Yes, I planned on pulling the bolt frm my freinds auger. But I do remember that when the orginal bolt sheared all that I could find was the hex head and it had the gr 5 hash marks. I will be axnious to see what the bolts look like that I had the dealer order from my parts list. I am sure that they will be grouved.
shear bolt revisited!!!!!!!
- Thread starter Deerlope
- Start date
- Views: 7881
<font color="#FF641A">I'm really surprised to learn a shear bolt would be a #5, so I did a little looking and found that some grade 5s can have different strengths. Check this out:
http://www.engineersedge.com/hex_bolt_identification.htm
Notice the different tensile strengths noted. John </font>
CK20Action
http://www.engineersedge.com/hex_bolt_identification.htm
Notice the different tensile strengths noted. John </font>
CK20Action
SacandagaBrad
Platinum Member
</font><font color="blue" class="small">( I remember a past thread [snow blower or rotary cutter, can't remember] where the manual had a misprint and the wrong grade was listed. Naturally, it was a harder bolt that was listed.. )</font>
Henro,
That was me. It was a Woods SS52 snowblower that came with a Gr 8 in the drive shaft and the misprint called for a Gr 8. I'm running Gr 2 now and have only used the blower once since we can't seem to get any more that 4 inches of snow at a time /forums/images/graemlins/frown.gif
I did use it once to cut back the banks and hit a stone just like the one that stopped the tractor dead in its tracks with the Gr 8, the Gr2 sheared like a charm, 2 minutes later had another in its place and back to work.
In Deerlope's case, the wood has a lot more give to it than a rock (all those years of geology school finally paying off /forums/images/graemlins/wink.gif). Maybe the shock absorbing tendency of the wood prevented the bolt from shearing, just like using a wooden mallet rather than a steel hammer. If it is easy to replace or you just don't often shear a bolt, try the Gr 2 or 3, they're cheap enough to try a few to see if they work for you without the risk of damage. I hope the dealer comes through for you.
Brad
Henro,
That was me. It was a Woods SS52 snowblower that came with a Gr 8 in the drive shaft and the misprint called for a Gr 8. I'm running Gr 2 now and have only used the blower once since we can't seem to get any more that 4 inches of snow at a time /forums/images/graemlins/frown.gif
I did use it once to cut back the banks and hit a stone just like the one that stopped the tractor dead in its tracks with the Gr 8, the Gr2 sheared like a charm, 2 minutes later had another in its place and back to work.
In Deerlope's case, the wood has a lot more give to it than a rock (all those years of geology school finally paying off /forums/images/graemlins/wink.gif). Maybe the shock absorbing tendency of the wood prevented the bolt from shearing, just like using a wooden mallet rather than a steel hammer. If it is easy to replace or you just don't often shear a bolt, try the Gr 2 or 3, they're cheap enough to try a few to see if they work for you without the risk of damage. I hope the dealer comes through for you.
Brad
kfgriffi
New member
When I bought my snowblower I also sheared the bolt that was providing power to the auger from the drive shaft. I did not have any grade bolts and quickly when through all the small bolts that I had. As a result I investigated what I needed to replace the bolt that sheared because I got so many different answers about what was need. I posted all the information I found in this forum and it can be found by following this link (you may have to cut/past): enter this forum url (tractorbynet.com/forums) and then append the following:
/parts-repairs/350222-everything-you-need-know-about.html#post4329972
BTW: A grade 5 bolt that is NOT threaded will require an additional 1,000lbs before failing...
CDN24
Member
After passing ? 200 lbs of gravel through my brand new 54" snow blower, I picked up a chunk of ice. The shear bolt snapped like a tooth pick. A bag of 4 came with it. I've cheated on shear bolts before; deerlope's thread tuned me up. Shear Bolts R' Us !
RPW
Veteran Member
- Joined
- Aug 12, 2009
- Messages
- 1,105
Shear bolts are grade 2. You can get them at your local hardware store and they're cheaper. If your shearing bolts you need to investigate why it's happening. In some cases it might be as simple as feeding to much material at a time. If you have the room you could add a slip clutch then you could replace the grade 2 bolts for grade 5. Good luck.
Rock knocker
Veteran Member
Source and context?
kfgriffi
New member
Please see my note it has the reference link described. I could not post the link directly because apparently you need to have a certain number of posts before you can put a link in directly. So I had to split it up into two parts. Put both parts together and enter that into the URL location bar and you will be brought to the page in this forum with all the details and references.
If you want quick data:
Size Size Surface area: Shear Tensil Shear Non Flange
(diam): (len): (Pi * r2) capability strength: Failure thread size
in ksi (lbs): len: (inch):
Grade 8
not threaded 0.25 1.25 0.049087385 90,000 150,000 4,418 0.3615
Grade 5
not threaded 0.25 1.25 0.049087385 72,000 120,000 3,534
Grade 2
not threaded 0.25 1.25 0.049087385 44,400 74,000 2,179
Grade 8
threaded 0.212 1.25 0.035298935 90,000 150,000 3,177 0.326
Grade 5
threaded 0.212 1.25 0.035298935 72,000 120,000 2,542 0.654
Grade 2
threaded 0.212 1.25 0.035298935 44,400 74,000 1,567
ksi = kilopound per square inch
1 ksi = 1000 psi (pounds per square inch)
Grade 5 not threaded - Grade 8 threaded: 357lbs.
(i.e. Grade 5 not threaded is stronger than Grade 8 threaded)
Shear capability is 60% of tensil strength.
Shear failure is shear capability x surface area.
kfgriffi
New member
Not all circumstances will use a grade 2 bolt for shear protection. In addition if you use a non-threaded grade 2 vs. a threaded grade 2 there is over 500lbs of difference. The specification for my Kubota snowblower calls for a grade 8 threaded bolt in the flange that connects the augers to the drive shaft. The difference from a grade 2 threaded to a grade 8 threaded is over 1,500lbs.
Bottom line is to check with the manufacturer of your equipment to identify what the requirements are for the bolt needed for shear protection.
RPW
Veteran Member
- Joined
- Aug 12, 2009
- Messages
- 1,105
kfgriffi- you are correct in your statement but for me I haven't met a piece of equipment that uses anything other than grade 2. Then again I also rarely see any snow let alone have to shovel any.
