Snow Shear bolt question

[Henro]

I may have missed it, but I have read each reply over the last few days...

Why not just ask the seller of the snow blower your question? Seems like they should know the answer...they took your money right?

 

[SylvainG]

Just got the blower (and tractor) today during a Winter storm so was able make good use of them right off the bat Turns out the spare auger sprocket shear bolts are grade 6.8 (written on its head), so not even SAE. They are 7mm x 50 mm long, so much longer than what the manual specified...

 

[jaydee325]

6.8 approx equal to SAE grade 2.

 

[Bavarian]

Just got the blower (and tractor) today during a Winter storm so was able make good use of them right off the bat Turns out the spare auger sprocket shear bolts are grade 6.8 (written on its head), so not even SAE. They are 7mm x 50 mm long, so much longer than what the manual specified...

6.8 is definitely a low grade that you find in every hardware store. But 7mm is unusual. 6mm or 8mm are regular metric thread sizes.

 

[WranglerX]

Grade 6.8 is roughly SAE Grade 2

And...

Metric Bolts - Minimum Ultimate Tensile and Proof Loads

Dale

 

[SylvainG]

6.8 is definitely a low grade that you find in every hardware store. But 7mm is unusual. 6mm or 8mm are regular metric thread sizes.

Hmm. could be a 6 mm. I measured it with my sliding vernier (the battery in my electronic one died) but didn't have my glasses on The manual says 1/4" so since 6 mm is its closest metric equivalent, must be it.

 

[Farmer495]

I have MK Martin blower (78"), new a few years back.

As stated in the operators manual it just uses regular hardware store bolts in the size listed. Easy and cheap to find, nothing special.

Mine came with several replacements in a cloth bag when it was delivered, were in the operator's manual holder tube.

I've broken that same shear pin you highlighted so I've changed them out.

 

[SylvainG]

Yes, I have the same 'cloth bag' with 5 shearbolts/locknuts, although they are metrics (6 mm) while the manual states SAE (1/4"). I guess less than 1/64th of a inch is close enough that it doesn't matter ( (1/4 - 6/25.4)*64 = 0.88 )

 

[Tinhack]

What is that, new math? :confused2:

Does that mean you accept 88% effective as "good enough"?

What else do you let slide? :laughing:

 

[CobyRupert]

.88 of 1/64th of an inch difference (i.e. .0138” is “less than 1/64th of an inch” difference)
I guess you could also say it’s 88% of 1/64th of an inch difference. Or .88/64th of an inch difference.
About 7/512th of an inch difference.
Or 1.38% smaller,
Or 98.72% to size and effective as “good enough”...

....somebody stop me....