(3) or (4) Bolts...

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pdq67
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(3) or (4) Bolts...

Post by pdq67 » Sun Dec 03, 2017 8:09 pm

Where can I buy (3) or (4), 3/8" dia. x 2-3/4" long UNF hex-head bolts in 300M quality??

I broke an ACE Hardware Grade-8 bolt that I was using to hold my mulch mower's, 21", "Gater", blade on with this morning so I want a stronger bolt!

Or somebody please tell me a better than Grade-8 bolt besides 300M quality to use in my application...

Thanks,

pdq67

PS., and I know that I am not supposed to be mulching 1" dia. sticks using my old commercial steel deck, green, Lawn-Boy mulch mower, but I do..

I installed a 5hp B&S engine on it and running about 1/2 throttle, boy does it mulch stuff up!!!

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Re: (3) or (4) Bolts...

Post by 1989TransAm » Sun Dec 03, 2017 9:26 pm

How about AN bolts that I believe are stronger than grade 8. I use them in certain applications. They in increments of 1/16" thickness. So an AN6 would be 3/8". An AN4 would be a 1/4", an AN8 would be 1/2" and so on.

Here is a link to one source. http://www.aircraftspruce.com/catalog/s ... nbolts.php

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Re: (3) or (4) Bolts...

Post by Keith Morganstein » Sun Dec 03, 2017 10:12 pm

pdq67 wrote:
Sun Dec 03, 2017 8:09 pm
Where can I buy (3) or (4), 3/8" dia. x 2-3/4" long UNF hex-head bolts in 300M quality??

I broke an ACE Hardware Grade-8 bolt that I was using to hold my mulch mower's, 21", "Gater", blade on with this morning so I want a stronger bolt!

Or somebody please tell me a better than Grade-8 bolt besides 300M quality to use in my application...

Thanks,

pdq67

PS., and I know that I am not supposed to be mulching 1" dia. sticks using my old commercial steel deck, green, Lawn-Boy mulch mower, but I do..

I installed a 5hp B&S engine on it and running about 1/2 throttle, boy does it mulch stuff up!!!
Caterpillar dealer nearby? The CAT bolts, grade 8 or 9 (some sizes are grade 9) are much better than what you buy at the hardware store. The price is good too.

Sometimes a higher grade bolt isn't better. On a brand of excavator I worked on, the track frames were bolted on with 1 1/2" dia bolts. Grade 8 bolts broke, but Grade 5 held up.
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Re: (3) or (4) Bolts...

Post by dave brode » Sun Dec 03, 2017 10:30 pm


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Re: (3) or (4) Bolts...

Post by pdq67 » Tue Dec 05, 2017 1:52 pm

How about if I have a local Machine Shop turn down (1) SBC 300M head bolt, shorten it to 2-3/4" long and then put a 3/8" UNF thread on it??

Would it hold up or would there be too many stress risers on it??

I figure the head bolt will have rolled threads is why I ask..

pdq67

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Re: (3) or (4) Bolts...

Post by Dave Koehler » Tue Dec 05, 2017 5:53 pm

Don't make this so complicated.
Go to CAT as suggested and get a bolt.
The only reason that the original broke is
1: You hit one hell of a rock and there is likely other damage.
or
2: The bolt has been over torqued repeatedly with an over enthusiastic impact.
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Re: (3) or (4) Bolts...

Post by pdq67 » Tue Dec 05, 2017 8:25 pm

Thanks Dave.

pdq67

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Re: (3) or (4) Bolts...

Post by Keith Morganstein » Wed Dec 06, 2017 5:06 pm

CAT part number 0L-0139

3/8"-24, 2-3/4" bolt length, 1.75" grip length,
9/16" hex head, phosphate and oil coated.
Prob around $2.00 a bolt.

Pick it up at a CAT dealer, authorized CAT truck or marine service shop, have one of these ship them to you or from cat parts online.
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Re: (3) or (4) Bolts...

Post by Keith Morganstein » Thu Dec 07, 2017 7:28 am

Keith Morganstein wrote:
Wed Dec 06, 2017 5:06 pm
CAT part number 0L-0139

3/8"-24, 2-3/4" bolt length, 1.75" grip length,
9/16" hex head, phosphate and oil coated.
0L-0139. List price $.81 ea
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Re: (3) or (4) Bolts...

Post by pdq67 » Tue Dec 12, 2017 6:07 am

I went out to our local Cat. Dealer and they didn't have any in stock like I want.

Would have to come out of St. Louis so I will just stop for now. I probably won't need my mulch mower until next spring.

Later,

pdq67

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Re: (3) or (4) Bolts...

Post by Dave Koehler » Tue Dec 12, 2017 9:07 am

MCMaster Carr 91257A662 pak of 10 $8.30

you know,...that may be the longest blade bolt I have run across.
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Re: (3) or (4) Bolts...

Post by pdq67 » Tue Dec 12, 2017 11:21 am

I have to admit that I MISS-TYPED, it's 1.75" long, not 2.75" long.

My bad.

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Re: (3) or (4) Bolts...

Post by MadBill » Tue Dec 12, 2017 10:39 pm

Some times what you need is a tougher bolt, not a stronger one...
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Re: (3) or (4) Bolts...

Post by pdq67 » Tue Dec 12, 2017 10:55 pm

Bill,

That is why I wanted 300M grade bolts because it is tougher than, "railroad spikes", imho!

pdq67

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Re: (3) or (4) Bolts...

Post by tjz450 » Wed Dec 13, 2017 1:20 pm

I suggest unbrako Allen head with harden washer. Without double checking specs AN bolts aren't better than grade 8,( G8's are too brittle). iirc.

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