# Cutting Edge Bolts Broke



## Redman7275 (Dec 2, 2016)

So I have a Fisher 8.5ft HD plow I bought used. By the end of the second storm 4 of the 8 bolts on the cutting edge snapped. I didnt think was too big of a deal until I tried to replace them. When I tried to take the broken bolts out of the holes I realized they were welded in, on both sides and so I had to torch them out. Then I went down to Napa and bought the bolts their manual said I needed. I get back to the shop and come to find out the diameter of the holes on the plow are a smaller diameter (1/2 inch) than those on the cutting edge (5/8inch)! The bolts fit snug in the holes on the plow, but have wiggle room on the cutting edge hole and spin when I attempt to tighten them down. I assume this is why the head of the bolts were originally welded to the cutting edge, but Im wondering if there is a way around this. I anticipate more broken bolts down the road so I would much rather not have to grind and weld the bolts on/off each time one breaks. Also any tips on how to tighten the carriage bolts without them spinning would be greatly appreciated!

Thanks Guys


----------



## Jeep_thing (Mar 3, 2014)

The bolts broke because the edge had room to move and shear them off.


----------



## leolkfrm (Mar 11, 2010)

sounds like a wrong edge, can have one punched with proper size or check on oem prices


----------



## Jeep_thing (Mar 3, 2014)

As far as I know carriage bolts are grade 5 at best, get grade 8 hex head bolts and use 2 grade 8 flat washers under each bolt head and also 2 under each nut, (make sure to get grade 8 nuts also!) lower the plow and cutting edge on jackstands or blocks so that the edge's pressure is pushing up and you have room to work, and crank down the nuts/bolts in fact torque them to 80 lbs. that should get you by on a budget.


----------



## dieselss (Jan 3, 2008)

Grade 5, washers and nylock nuts.
Recheck the tightness after first storm.


----------



## Redman7275 (Dec 2, 2016)

The plow was "refurbished" by the last owner so I'm almost sure its not the OEM blade. Jeep_thing, I had the same thought as you. As long as the cutting edge is pushed up when its tightened down then the repetition of dropping the plow shouldnt cause too much of a problem. Im definitely on a budget seeing as how this is my first year plowing for myself and we barely have gotten any snow!


----------



## Randall Ave (Oct 29, 2014)

Before you bolt it up. Remove the edge and make sure both surfaces are clean,


----------



## Jeep_thing (Mar 3, 2014)

Redman7275 said:


> The plow was "refurbished" by the last owner so I'm almost sure its not the OEM blade. Jeep_thing, I had the same thought as you. As long as the cutting edge is pushed up when its tightened down then the repetition of dropping the plow shouldnt cause too much of a problem. Im definitely on a budget seeing as how this is my first year plowing for myself and we barely have gotten any snow!


The key is using all grade 8 hardware (gold in color) so that soft washers don't get sucked down into the oversized holes. Also being able to torque to 80#, they should not loosen. Don't need locknuts.


----------



## dieselss (Jan 3, 2008)

Jeep_thing said:


> The key is using all grade 8 hardware (gold in color) so that soft washers don't get sucked down into the oversized holes. Also being able to torque to 80#, they should not loosen. Don't need locknuts.


Grade 8 comes in different "colors" gold is just the coating.
Unless you use a lock washer, or some form of locking nut, the nut WILL come lose.
I've found that loctite and a nylock and retighten worker the best


----------



## Randall Ave (Oct 29, 2014)

OP are you sure its punched out for 5/8? The square hole will be very large. I have always used grade 5 , Id rather pop a bolt than break something else. Mine are on with lock washers and nylock nuts. Torqued with my ingersal rand torque wrench.


----------



## Jeep_thing (Mar 3, 2014)

dieselss said:


> Grade 8 comes in different "colors" gold is just the coating.
> Unless you use a lock washer, or some form of locking nut, the nut WILL come lose.
> I've found that loctite and a nylock and retighten worker the best


Yes I'm certainly aware the 'gold' is a cadmium plating used to identify the grade along with the bolt head markings. He would be hard pressed to find grade 8 hardware that is not 'gold' in color.


----------



## dieselss (Jan 3, 2008)

https://www.fastenal.com/products/f...1 Bolts"|~ ~|categoryl3:"600025 Plow Bolts"|~

Plain finish.....


----------



## 1olddogtwo (Aug 6, 2007)

dieselss said:


> https://www.fastenal.com/products/fasteners/bolts/plow-bolts?r=~|categoryl1:"600000 Fasteners"|~ ~|categoryl2:"600001 Bolts"|~ ~|categoryl3:"600025 Plow Bolts"|~
> 
> Plain finish.....


Have you ever tried sex bolts?


----------



## dieselss (Jan 3, 2008)

1olddogtwo said:


> Have you ever tried sex bolts?


I take the 5th......there wasn't supposed to be cameras there


----------



## Randall Ave (Oct 29, 2014)

1olddogtwo said:


> Have you ever tried sex bolts?


What you talken bout Willis


----------



## LapeerLandscape (Dec 29, 2012)

1olddogtwo said:


> Have you ever tried sex bolts?


Fine thread or coarse.


----------



## theplowmeister (Nov 14, 2006)

Fisher carriage bolts are grade 8 (the last batch I got from FISHER NOT Napa)


----------



## ktfbgb (Jan 31, 2016)

Jeep_thing said:


> Yes I'm certainly aware the 'gold' is a cadmium plating used to identify the grade along with the bolt head markings. He would be hard pressed to find grade 8 hardware that is not 'gold' in color.


That's strange, I use the black oxide grade 8 bolts all the time where corrosion isn't a concern. Readily available anywhere I go for them.


----------



## tbone1471 (Jan 18, 2012)

Sounds like your cutting edge is wrong. 

We use grade 8 hardware to assemble. Make sure the surfaces are clean and free of salt and rust. 1/2" air impact to tighten down. Once all bolts are tight take a 5 lb hammer and smack every bolt on the head. No mercy. Retighten. This part is key. Might sound stupid but they tighten up a good bit more.

This is how we do our highway plows. Works great.


----------

