Is it okay to replace fine thread frame bolts with coarse thread?

[belfert]

I found one of the the bolts when putting things back together so only missing one bolt now and some nuts that fell on the ground.  I ended up buying the coarse thread bolts at the hardware store since I can't find anyone who has the right bolts in fine thread with the proper jam nut unless I want 100+ of them.

The nuts that I bought with the new bolts are lock/jam nuts and they were hard to get tightened on the bolts.  The original nuts were also jam/lock nuts and are somewhat hard to get tight.

[Stan]

Brian: I think this is the first post where you mentioned lock nuts. I think you are over concerned about the replacement bolts when you have no concern about reusing lock nuts. Depending on the type, many are a one use and then throw away, while ones like on an Allison output shaft can be used up to three times.

[TomC]

I learned long ago when doing a take apart project to use a tuperware bowl or old coffee can for the nuts and bolts.  Believe me it will save you alot of time and aggravation.  Good Luck, TomC

[belfert]

Brian: I think this is the first post where you mentioned lock nuts. I think you are over concerned about the replacement bolts when you have no concern about reusing lock nuts. Depending on the type, many are a one use and then throw away, while ones like on an Allison output shaft can be used up to three times.

The frame bolts and nuts that I reused still seem to have plenty of lock left in them.  The nuts are all metal and they are still very difficult to tighten so they seem to still lock okay.

I would be happy to replace all of the frame bolts if I could FIND any.  Every place that has these in fine thread has a minimum of 100 and in many cases minimums of 300 to 2000.  Fastenal, McMaster-Carr, and MSC all have the bolts, but not the flare lock nuts.  Just about every hardware store has these in coarse thread.

[Dallas]

Brian....

Check with Mac's Hardware, even though there isn't one in the Cities, that's where the main offices are.

They sell bolts and nuts of all shapes sizes sorts and kinds by the pound. Possibly they'll make you a good deal.

I think the closest store to you is Detroit Lakes, but, Hey, you probably need a break anyway.

MAC'S INC. MINNEAPOLIS, MN OFFICE:
8816 7th Ave. N.
Golden Valley, MN 55427
(763)544-0588 • Fax: (763)544-0607
(800) 390-8265

[belfert]

Detroit Lakes would be a really long drive.  It would be somewhere around 4 to 5 hours each way.  Moorhead would be a bit closer I think, but still a long drive.

I'm not sure calling would be worthwhile as most folks at hardware stores get confused once you get beyond standard nuts and bolts.

[JohnEd]

Belfert,

No!

John

[kyle4501]

Belfert,

No!

John

OK, I'm a little slow, what did I miss? 

[Stan]

My personal opinion is that you could put six 1/2 X 13 grade 2 bolts in and tighten them with a pair of pliers they would probably last as long as you own the coach.

I don't think you have six 1/2 X 20 grade 8 bolts holding in your 400 HP engine. That size and grade have a tremendous amount of strength in both tension and shear. If you are only missing two in your rad frame, put in a couple of bolts and snug them up and get on with more important things.

As end users, we don't know why a manufacturer used a particular component although the usual reason is cost. If they can use the same fastener in multiple places they get a bigger volume discount that more than makes up for using a better bolt than ordering a smaller quantity of two different bolts.

Years ago I ordered some 1 1/4" long oval head Phillips Stainless bolts from MCI and was shocked at the price. When I checked the price book, I found that I could have ordered 1 1/2" for less than half price. This was a simple case of the relative volume they used of each length.

[belfert]

My personal opinion is that you could put six 1/2 X 13 grade 2 bolts in and tighten them with a pair of pliers they would probably last as long as you own the coach.

I don't think you have six 1/2 X 20 grade 8 bolts holding in your 400 HP engine. That size and grade have a tremendous amount of strength in both tension and shear. If you are only missing two in your rad frame, put in a couple of bolts and snug them up and get on with more important things.

You're absolutely right on this.  I gave up looking for fine thread bolts a few days ago and just replaced most of the bolts with new coarse thread ones that any good hardware store stocks.  Not cheap at $3 for the bolt and nut, but what is cheap on these buses?

[Stan]

Is there only one hardware store in town. I have a choice of three  in a town of about 15000 people and they all sell bolts by the pound. Grade 5 bolts, nuts, flat and lock washers $1.89/pound. Same thing in Grade 8 is $2.89/pound. The cheapest thing I bought for a bus.

[belfert]

Is there only one hardware store in town. I have a choice of three  in a town of about 15000 people and they all sell bolts by the pound. Grade 5 bolts, nuts, flat and lock washers $1.89/pound. Same thing in Grade 8 is $2.89/pound. The cheapest thing I bought for a bus.

These are special grade 8 bolts and nuts with flared heads.  The nut is also an all metal lock nut while having the flare.  These are not standard grade 8 fine thread bolts.

They are also known as frame bolts.  I went to three auto parts stores, a truck parts place, and numerous hardware stores looking for these in fine thread.  They all had these bolts in coarse thread.  I also went to Fastenal and checked McMaster-Carr.  McMaster and Fastenal had the bolts in fine thread, but not the special lock nuts.  I also checked numerous web sites, but they all wanted to sell a minimum of 100 with minimums of 300 and up more common.

[Stan]

Brian: I was referring to your paying $3.00 for each bolt and nut at the local hardware.

[RJ]

Brian -

I know I'm jumping into this thread a little late, but this might help for "next time":  Ask at an auto body shop if there's a company in town that supplies them with their specialized nuts, bolts and washers.

Here in Fresno, there's a little "hole-in-the-wall" office in the middle of one of those strip industrial parks that has a HUGE assortment of automotive and ag equipment fasteners of all types, from serrated flange nuts and bolts to the large fender washers - they even carry the clips to mount door panels.  This place was referred to me by a friend who owns an auto body shop, and what a great tip it has turned out to be.

I've often found what I've been looking for at this place, after exhausting the big box and mom & pop hardware stores.  So check into it, I'm sure there's something similar in the Twin Cities area.  (And no, this isn't a Fastenal branch, altho we do have one here in Fresburg.  This is an independent.)

FWIW & HTH. . .