What Grade bolt is this?

[brokenknee]

This is the bolt that is on my trap-setter, was wondering what grade of bolt it is. I did search the internet but was not able to find a marking like it.

 

[Mysfyt]

Grade 2.

 

[murphy1244]

Grade 2.

^+2^.

 

[brokenknee]

Thank you, I was reading a review on another trap-setter and the person doing the review stated that his bolt broke when trying to set his 330. I was just wondering if I should replace it with a grade 5 stainless. The reason I would go stainless as this is an aluminum setter. It does have sheet metal over the pivot point, I think for added strength. I am also considering pulling those off and placing some rubber pond liner I have on hand between the two.

The reason for this is because I am concerned about electrolysis of the metals.

The largest trap I have is a 220, 330 is not allowed above water in MN from what I understand, and I have no intention on going out trapping beaver.

 

[Mysfyt]

Stainless tends to 'gall' as a pivot and is usually not recommended for that purpose, but might be OK for your situation. Grade 5 would be my choice and lube it every now and then.

 

[brokenknee]

Stainless tends to 'gall' as a pivot and is usually not recommended for that purpose, but might be OK for your situation. Grade 5 would be my choice and lube it every now and then.

Will the lube cut down on the electrolysis?

Any suggestions on the sheet-metal covering the aluminum?

 

[Oldtink]

Here is a pdf file on dissimilar metal galvanic corrosion and how to over come it or at least fight it.
http://www.pdhonline.org/courses/s118a/s118content.pdf

 

[brokenknee]

Here is a pdf file on dissimilar metal galvanic corrosion and how to over come it or at least fight it.
http://www.pdhonline.org/courses/s118a/s118content.pdf

Thanks for the link. According to the chart galvanized and zinc covered metal corrosion is considered insignificant.

 

[TractorGuy]

Here is a list of bolt grade markings and their strengths.

This list has a more specific list of strengths for different size bolts.

Bolts with non-typical markings may not be made to any specific code. Check the one you have with a magnet to see if it's an off brand stainless.

You should not automatically increase bolt strength grades. Certain applications require certain properties. A grade 2 bolt will have greater stretch before failing than a grade 5 and provide a cushion of sorts when forces exceed it's strength. I can give an example of this. Back in the 90s some school buses had the seats attached with grade 8 bolts. Studys found that during a crash these bolts would fail suddenly and cause greater injury. A recall was issued to replace all the seat bolts with grade 5. The grade 5 bolts while not having the same tensile strength would stretch and create some cushion when they failed.

Some PTO driven implements that use a shear bolt will require a grade 2 bolt to protect the gear boxes. People often replace those with grade 5 or 8 bolts to reduce the frequency of failure but they do so at the risk of damaging the gear box or PTO components.

 

[brokenknee]

Here is a list of bolt grade markings and their strengths.

You should not automatically increase bolt strength grades. Certain applications require certain properties. A grade 2 bolt will have greater stretch before failing than a grade 5 and provide a cushion of sorts when forces exceed it's strength. I can give an example of this. Back in the 90s some school buses had the seats attached with grade 8 bolts. Studys found that during a crash these bolts would fail suddenly and cause greater injury. A recall was issued to replace all the seat bolts with grade 5. The grade 5 bolts while not having the same tensile strength would stretch and create some cushion when they failed.

Some PTO driven implements that use a shear bolt will require a grade 2 bolt to protect the gear boxes. People often replace those with grade 5 or 8 bolts to reduce the frequency of failure but they do so at the risk of damaging the gear box or PTO components.

I have had to replace the shear bolt on my brush hog, I always use the cheap bolt to protect my gearbox.

My concern would be the bolt failing while in the process of setting my trap and have something go flying causing damage or injury to anyone that happens to be around it.

In the case of the school bus bolts, I would think that they would have sheared off at a lower impact.