Grade 5 Or Grade 8 For Winch?

Wow! Very informative. Thanks everyone.

Sounds like a fine thread grade 8 is the way to go? There are no torque specs in the instructions so I guess I will use my TFAR wrench I inherited from Dad. (That Feels About Right).

Thanks again.
Steve
(Maybe someday someone will ask I question I can answer)

 

It always gets brought up that Grade 5 will stretch and such, as mentioned above.

Grade 8 will always be stronger than Grade 5, that's just how it is.

I'd be more worried about the casting of the winch breaking than the bolt securing it.

I know that 99% of the winches today are made of cast aluminum.

I use Grade 8 for mounting EVRYTHING...if I'm replacing any bolt due to rust or whatever it's getting upgraded to Grade 8.

They even make "Grade 9" bolts nowadays lol.

Make sure you buy your hardware from a legit fastener store. I've found that some of the "Grade 8" hardware from places like Ace Hardware and Lowe's aren't Grade 8... they're cheap chinese junk and they shear.

I always put copper anti-seize or loctite on my bolts too. They're either a permanent addition or they'll be removed at some point so make sure you use the proper lube or locking compound depending on the purpose.

 

Picked up the bolts today. The nuts are something new to me. They are like a Nylock but all metal. Can't remember what he called them. No lock washer required. Do I still need thread locker with these nuts? or Antisieze?

I do intend to remove this at some future date when I figure out what kind of bumper I want to build to replace the cheap chrome looking thing on there now.

Thanks,
Steve

 

Antisieze is never a mistake in anything used outdoors. Believe it, but stainless will actually rust under some conditions. Especially if you use your jeep in the rust belt, in winter

 

Are you SURE those nuts are grade 8? They have a slight crimp to the top, deforming when run down on the bolt. Grade 8 hardware isnt known for deforming like that.

If mine I'd use grade 8 hardware: bolt, washer under head, washer and lock washer under nut. All of it grade 8. And red loctite. No anti-seize. I use anti-seize a LOT, but there are places where I will not use it: winch mount, steering box mounts, hitch mounts, tow points.

 

I used it once on my wheel lugs. That was definitely a mistake...

 

McMaster-Carr

Ok, there are distorted grade 8 nuts.

When using amti-seize one should back off on torque specs. Stuff is so slippery you'll tear up equipment if you dont adjust. I think rule of thumb is back off by 15-20%? If used on Harley cyl head studs you rip them out of the block if you use anti-seize and follow the torque spec which assumes engine oil for thread lube.

 

ive seen in manuals where a torque spec is not specifically given for a certain bolt but there is a table for all of those depending on size...i would think that info should be available
7/16 fine thread grade 8 = ft/lb
etc
etc

 

Because it's already leaking before you get it back together?

 

Wait. Did I just get dinged with a leaky Harley joke on a JEEP FORUM?!

 

I think the moral of the story is...........a Grade 8 will out perform a grade 5 for a small increase in cost.........

• Nylok nuts or other forms of locking nuts do not require any thread locking liquid. In fact it's been said that some Loctite liquids on a Nylock nut will attack the nylon locking ring...........
• Anti Seize is a good idea around bolt threads that see heat or may see moisture all the time. Anti Seize is also a good Idea on Stainless fasteners ........
• Washers under the head and on top of the nut allow for a tighter grip and less friction when torquing ......and if you want it to stay tight Torque it to the specific value for size and thread pitch................
• And if your looking for a 3/8" diameter bolt to clamp a 1/2" hole in a bracket and stay tight .....that will probably never happen........worn out holes should be resized to the next size up and clamped with the next bolt size up..............
• And in the aircraft & racing world the shoulder of the bolt and not the thread is what comes in contact with the hole diameter and bracket that keeps the assembly together....and that hole and bracket size are both kept to tight tolerances......These Bolts are sold in specific shoulder grip lengths to accomplish that...

 

Steel Bolt Torque Specifications Table - Engineer's Handbook

 

I've been working on heavy machinery for near 40 yrs. We don't consider anything less than grade 8. Use some titanium bolts also.

 

Thanks again everyone...

The nuts are not nylocks. Something called "all metal hex lock nut". First time I've seen or used them.

I wasn't sure what size to get so I got a set of 1/2 inch and a set of 5/8 inch. I got enough of each for 3 bolts on each side of the plate. I also went with standard thread instead of fine thread.

I'm thinking the 1/2 inch stuff will be big enough. It just looks to me that a 5/8 hole in the frame will take too big a chunk out of the frame. What say you?

Got a long Thanksgiving weekend coming so I am hoping to get some stuff bolted together.

Thanks again for all the input.

Steve

 

The all metal deformed nuts are sometimes referred to as pinch nuts or aircraft locking nuts also depending on who you talk to. Common in automotive and are considered one time use only.
There are circumstances when a coarse thread is desirable over a fine thread. When the threads are in a softer material like aluminum for example. The coarse threads are significantly deeper on the bolt than fine threads so a fine thread can strip in softer material when a coarse thread will hold up just fine.

 

FinoCJ....these are the nuts. Are those the dimples on the shoulder you are talking about?

 

That is a toplock lock nut.

 

Various types of safety wire drilled aircraft bolts center to far right / Grade 8 center top / various sized and spec'd aircraft locking nuts and jamb nuts that are safety wire drilled..../ SAE / NAS washers for various uses / far left Titanium bolts....................Every Bolt , washer & nut has a specific use.

 

I used grade 8 -1/4" bolts to hold the wheels on my gokart so they were basicly acting like a sheer pin. They sheered quite often. I switched to grade 5 and they hold up fine. From what I gather if a grade 5 is insufficient you just need a bigger bolt not a stronger one. Personally I dont like how they can sheer without warning. With a grade 5 it tends to bend or strip. A grade 8 just snaps. I was cutting tire chains today one of them was hardened i cut one side of the link and the whole thing snapped in two. Anyhow for a winch im sure either one is fine