Crow Bar

[Arbo]

Today at work, I thought I would weld up a broken crow bar. What the heck are they made of? It sparked like steel from the grinder. When I welded It gave alot of excessive spatter, and acted like cast iron. I ran a bevel and multi pass with .035 flux core on it and the welds looked good. I tried it out on an immovable object when I was done. I gave it everything I had, and it seemed to hold. I was just wondering what type of steel it might be.

[morpheus]

I think they're made out of cast steel.

- jack

[Rocky D]

That's a real good question...I have welded scores of them, but never did know what steel the were using. I do know it is very dense material, and they will break in the HAZ (heat affected zone) lots of times. Cast steel welds pretty much like HRS, (hot rolled steel) but it could be tempered, I suppose.

[Bob]

I must lead a sheltered life. I have never had a broken crow bar. They seem to give quite a bit, but I guess they don't permanently bend ... so you just have to go to far and it snaps?
Bob

[Arbo]

The breakage usually occurs when somebody is trying to do something that the tool isn't made for. Like using a forklift to apply the pressure, or beating on it with a sledge hammer. Today was the sledge hammer that did this one in.

[Rocky D]

Originally posted by Bob
I must lead a sheltered life. I have never had a broken crow bar. They seem to give quite a bit, but I guess they don't permanently bend ... so you just have to go to far and it snaps?
Bob

Yes, sometimes guys will use a six foot cheater pipe to pry up a 10 ton machine. The machine wins.

[Roger]

Cast steel?

Lots of tools are forged, squirt white hot steel into bottom die then close top die with lots of force to make steel take shape forming part with desired grain structure.

[morpheus]

what's the difference between casting and forging ? from your description it sounds like force is the difference.

- jack

[Bob]

Rocky D,

Ah yes. I did that once to a 1/2" Craftsman breakover wrench: 250 ft-lbs on the rear axel nuts of a VW bug.

Someone did that 150 miles SE of you. Mag 4.8 quake just after 1 pm yesterday. Felt as far away as up past Oceanside.

Bob

[BillC]

Originally posted by morpheus
what's the difference between casting and forging ? from your description it sounds like force is the difference.
- jack

Forging involves placing a solid part into a set of dies and plastically deforming it into the desired shape. This is typically a multi-stage process with different cavities to progressively turn the initial shape (commonly round bar) and turn it into a final shape (like a revolver frame). The round bar can be hot or cold. The drop forging process that I visited lifted and dropped a one ton die at a frequency of one impact every one or two seconds. Watching the operator manually place the workpiece into the cavities in between drops was amazing.

I am not a manufacturing engineer, but I have never heard of pouring metal to be forged. Casting is just that; pouring molten metal into a mold and letting it cool.

Roger, what kind of forging uses molten steel?

[Rocky D]

Originally posted by Bob
Rocky D,

Ah yes. I did that once to a 1/2" Craftsman breakover wrench: 250 ft-lbs on the rear axel nuts of a VW bug.

Someone did that 150 miles SE of you. Mag 4.8 quake just after 1 pm yesterday. Felt as far away as up past Oceanside.

Bob

Bob, do you have a line on any ocean-front property in Phoenix, yet? We may be looking for some!

[Roger]

I once saw film clip of die lock chain being made. Amazing process. The steel as I remember it was bar just short of a liquid as formed into chain. All USN ships use die lock chain for their anchors. ASR21 and ASR22 Submarine Rescue ships carried enough chain to 4 point moor over submarine on bottom at 1000 ft. Miles of chain. Chain was so heavy they had to use 2 capstans to raise it from 1000 ft. They also had anchor chain for their normal ships anchors at each corner. You can't drop anchor over 90' and stop it with the capstan's brake it has to be lowered.

All of the other ASRs used wire rope for most of each leg of 4 point salvage moor. Layed the mooring out on deck so each leg could be droped as the ship traveled a race track course or a clover leaf course.

[John Stuckey]

Bob:
Thanks for the memories about the VW rear axel nuts and Craftsman breaker bars with lots of pipe attached! I laughed out loud reading your piece.
John

[Bob]

John,

My bug is '73. Drove it to work today.

I took an 18" length of 3/8 flat bar and cut two 1/2" square holes in it. Standard torque wrench snaps in one hole, 1/2'"bar stock in the other drives the socket. Double the length means twice the torque so I do the 250 ft-lbs with half that reading on the standard wrench.
The part I thought was funny, was it is a castle nut and gets a cotter pin AFTER the 250 ft-lbs.

I snapped the breakover getting one of those off. The 1/2" bar stock is only good for about 1 or 2 tightenings before it distorts and breaks.

Bob

[Roger]

Impact wrench or special socket with hammer flat is only practical way to remove VW bug/van axle nut. Same is true for removing Mazda flywheel nut for rotary engine and boat prop nut.

To remove nut holding ship's screw, used real big wrench pulled by crane.