Shear Pin Question

[navajo001]

First off, I want to thank you guys again for helping me with questions about fitting on a tractor. Tilt steering! Who knew?

Anyway, my new Kioti CK3520SE was delivered Tuesday with various attachments including a rotary cutter but no spare shear bolts.

So, I looked around in here then downloaded the cutter manual and it said (and you guys bore this out) Grade 2 bolts 1/2"x3" for the kioti. But how to tell the grade? I read up online about how to tell the difference and it seemed that mostly if the head had no marks, it's grade 2, grade 5 have 3 stripes and grade 8 have 6 stripes. So I went to Lowe's tonight to stock up before I hit the fields this weekend but every bolt there has letters stamped on the heads (I assume manufacture initials etc from what I saw) and the young dude "helping" had no idea.

BUT, they had a section clearly labeled GRADE 5 and one for GRADE 8, but nothing anywhere saying grade 2. So I left.

On the drive home, it hit me, if there are NO markings other than initials etc, doesn that mean they are grade 2? In other words, if they aren't specifically marked Grade 5 or 8, are all others default grade 2?

I don't want to tear anything up.

Thanks for reading!

tom

 

[ROUSTABOUT]

First off, I want to thank you guys again for helping me with questions about fitting on a tractor. Tilt steering! Who knew?

Anyway, my new Kioti CK3520SE was delivered Tuesday with various attachments including a rotary cutter but no spare shear bolts.

So, I looked around in here then downloaded the cutter manual and it said (and you guys bore this out) Grade 2 bolts 1/2"x3" for the kioti. But how to tell the grade? I read up online about how to tell the difference and it seemed that mostly if the head had no marks, it's grade 2, grade 5 have 3 stripes and grade 8 have 6 stripes. So I went to Lowe's tonight to stock up before I hit the fields this weekend but every bolt there has letters stamped on the heads (I assume manufacture initials etc from what I saw) and the young dude "helping" had no idea.

BUT, they had a section clearly labeled GRADE 5 and one for GRADE 8, but nothing anywhere saying grade 2. So I left.

On the drive home, it hit me, if there are NO markings other than initials etc, doesn that mean they are grade 2? In other words, if they aren't specifically marked Grade 5 or 8, are all others default grade 2?

I don't want to tear anything up.

Thanks for reading!

tom

You had the no grades in your hand. No slashes means not 5 or 8. Usually 3 is five, five is 8 and six is 10. But I was almost wrong once before and this may be one of those close calls. Metric bolts have a decimal number on the top. Stick with SAE bolts. You need double nuts jammed together, or nylock lock nuts, on that shear bolt. That way it won't come loose while you are in the middle of doing something, have to stop and put it back together to continue. Get a few extras.

 

[5030]

The stuff at a hox store like that is probably Chinese anyway so grade will be questionable no matter what.

 

[ptsg]

Leaving this here for reference.

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[yooperdave]

First off, I want to thank you guys again for helping me with questions about fitting on a tractor. Tilt steering! Who knew?

Anyway, my new Kioti CK3520SE was delivered Tuesday with various attachments including a rotary cutter but no spare shear bolts.

So, I looked around in here then downloaded the cutter manual and it said (and you guys bore this out) Grade 2 bolts 1/2"x3" for the kioti. But how to tell the grade? I read up online about how to tell the difference and it seemed that mostly if the head had no marks, it's grade 2, grade 5 have 3 stripes and grade 8 have 6 stripes. So I went to Lowe's tonight to stock up before I hit the fields this weekend but every bolt there has letters stamped on the heads (I assume manufacture initials etc from what I saw) and the young dude "helping" had no idea.

BUT, they had a section clearly labeled GRADE 5 and one for GRADE 8, but nothing anywhere saying grade 2. So I left.

On the drive home, it hit me, if there are NO markings other than initials etc, doesn that mean they are grade 2? In other words, if they aren't specifically marked Grade 5 or 8, are all others default grade 2?

I don't want to tear anything up.

Thanks for reading!

tom

ASTM A307 (structural) is nearly identical in strength to SAE Grade 2 (mechanical). The top is clean with no marks. This is the cheap grade you can buy at nearly any hardware store.

Yooper Dave

 

[WranglerX]

Your grade 2 bolt with initials were probably price codes for cashier...

Tractor Supply has grade 2 and grade 5 and and maybe grade 8 by the pound..... Probably all Chinese counterfeits though... Use a lot of grade 2 around property for non critical things, have not has any failures yet...

 

[5030]

I always look at the head of a bolt or machine screw to see who cold headed it. Habit I guess. I tend to buy LE, which is Lake Erie screw Company, located in Lakewood, Ohio, near where I grew up.

I also suspect that every fastener stocked at Tractor Supply came here in a container. TSC is real good for selling Chinese stuff.

 

[navajo001]

Thanks everyone! So, I know not to use grade 5 or 8 bolts for a shear bolt, and since I'm not sure what the other bolts with no hash marks from Lowe's are, I'll swing by TSC next time I'm out that way and see if they can help. Other than that, I can order a pack from Rural King since they have it labeled on the 5 pack package on their website. Was just hoping to have them this weekend and bolt then got flustered trying to figure out the Lowes stuff. After driving an hour to get there.

 

[RustyA]

Your new cutter doesn't have a slip clutch on it does it? Round contraption on PTO shaft near gear box with adjustable springs with bolts through them. That would not require a shear bolt as the clutch performs that function.

 

[cathy liebchen]

Add a slip clutch