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ligito
01-30-2010, 06:42 PM
I need to press some carriage bolts into flat bar.
The carriage bolts are 3/8 - 16 and the flat bar is 1/4 x 4 in,
What hole size do I need to accomplish this?

I'm extending the forks by 4 inches, on my Walkie Stacker.
My load will not exceed 900 lbs, the original forks are 26 in and I'm extending them to 30, to pick up an ATV and stack it on pallet racks.

Is there another preferred method of attaching the extension to the forks?

gda
01-30-2010, 06:51 PM
I'm not sure I understand how you are trying to attach the extenders, but 1/4" stock sounds flimsy. You may only want to lift 900# but they also need to be strong enough to take the "crash" abuse they will see.

Every fork extender I have ever seen has been basically a piece of rectangular tube stock slid back onto the full length of the fork, and just as long as needed.

ligito
01-30-2010, 07:01 PM
This is a fork over leg type stacker, so the forks are channel and I'm just adding 4 inches to the length, to get all of the way under the frame on an ATV, because at 26 inches, it still has a way to go.

I'm bolting the 4 inch x 1/4 flat bar on the top of the forks.

This stacker will be used in a residential garage and not be used very many times a year.

Black_Moons
01-30-2010, 07:15 PM
Pressing bolts? Like just drilling a round hole and letting the square part of the shaft broch it into a square? Intresting if thats the case, I never thought carriage bolts could be used like that.

Carld
01-30-2010, 07:26 PM
Carriage bolts are soft bolts. The square under the head will not deform as you think when pressed in a hole, especially in a fork on a lift. Also the fork is hard steel. You need grade 8 bolts.

1/4" thick bar stock is not thick enough to lift the ATV safely.

How long are the forks now? How far past the end of the present fork will the 1/4" bar stick out?

PeteM
01-30-2010, 07:41 PM
I've used a square file to open up holes to get carriage bolts to seat properly. But as noted, carriage bolts are Grade 2 at best and shouldn't be trusted.

"Elevator bolts" are available in stronger grades and also have flat heads.

Paul Alciatore
01-30-2010, 09:56 PM
Carriage bolts are designed to press into WOOD, not metal. As stated above, they are soft steel, probably grade 2 or 3. Unless you are going into soft aluminum, this is not the way to do it. If you punch or file 3/8" square holes, it may work.

If you can't put a wrench on the bolt heads, it may be better to weld studs on the plate. Or, assuming that more than one would be required, make some U bolts from threaded rod with 90 deg corners so they each fit two adjacent holes.

true temper
01-30-2010, 10:35 PM
I have seated carrige bolts in 1/4" flat bar using this method. First drill the hole a bit bigger than the dia. of the bolt. Them using a press push a large square tapered ezyout in the hole. Makes a nice square hole. flip the flat bar over and grind it flat and it will look like a broched hole.

Arcane
01-30-2010, 11:22 PM
I have seated carrige bolts in 1/4" flat bar using this method. First drill the hole a bit bigger than the dia. of the bolt. Them using a press push a large square tapered ezyout in the hole. Makes a nice square hole. flip the flat bar over and grind it flat and it will look like a broched hole.

That's a pretty slick idea! I'm definitely gonna steal it! :)

winchman
01-31-2010, 12:39 AM
Sounds like you could use some wheel studs:

http://www.hunt4steve.com/OR/05Taco/ext/ln/610-462-1.jpg

Dorman sells them at most auto parts stores in a variety of sizes and lengths.

The serrations pull into the plate when tightened, and the heads will be nearly flush.

ligito
01-31-2010, 12:51 AM
The flat bar only extends 4 inches beyond the 26 inch forks and most of the weight is on the first 24 inches of the forks.

Wheel studs were my other choice but I didn't find them at the hardware store.
If the make them as small as 3/8, I will get some.
They are a lot easier to press in.
I have a 12 ton press.

cuemaker
01-31-2010, 09:33 AM
Just a FYI as I think pressed studs will work also............

There is a carriage bolt that is grade 8 called a plow bolt...Dome head bolt also almost the exact same thing, just a slightly different head..

You can also find ribbed necked carriage bolts in all kinds of grades...

ligito
01-31-2010, 12:16 PM
Thanks, I ordered some wheel studs from NAPA that have a 5/16 shoulder length and are 7/16-20 thread.

These are going into the flat bar, not the forks.