Cutting steel math question

[Soft Cars]

OK so if I was to buy a full 4 ft. x 8 ft. sheet of 1/8 in. thick mild steel plate, how many 2 in. x 8 in. pieces could I get out of that?

Correct me if I'm wrong:

48 x 96 = 4608 square inches.

2 x 8 = 16 square inches.

4608 divided by 16 = 288.

So am I right? 288 pieces out of a full sheet?

 

[UG_Passat]

Theoretically, yes, but you have to take into account the thickness of the cutting blade. That's going to eat into the measurements and adds up over the cuts. So, 288 would be the max in a perfect world, but it's somewhere a little less than 288.

 

[Soft Cars]

OK I'm assuming the metal shop would use a hydraulic shear to cut the pieces. How much waste would that be?

 

[joegreen]

Maybe they use some type of water jet

 

[Soft Cars]

They have a CNC laser cutter but I think it's for odd shapes. All I'm wanting is a bunch of rectangles.

 

[Danno]

It depends on the method used to cut the steel. Talk to a shop, they will tell you.

 

[Kira]

Shears don't have much kerf but the ones I've seen warp the coupon a bit.

 

[97K15004WD]

Don't know for sure, depends on how they cut the coupons. I'd say for planning purposes to "lose" one row and one column.

So, your max minus that amount.

From my perspective, no different than if I was cutting those out of a sheet of plywood.

 

[Skippy722]

Maybe they use some type of water jet

Water jets have a kerf of ~0.020”~0.060”.

A sheared edge will look like this.

 

[MasterSolenoid]

Theoretically, yes, but you have to take into account the thickness of the cutting blade. That's going to eat into the measurements and adds up over the cuts. So, 288 would be the max in a perfect world, but it's somewhere a little less than 288.

Yes
and a .... +/- tolerance

 

[racer12306]

Don't know for sure, depends on how they cut the coupons. I'd say for planning purposes to "lose" one row and one column.

So, your max minus that amount.

From my perspective, no different than if I was cutting those out of a sheet of plywood.

This was my thought. From the perspective of not having all the info, this is pretty safe since the rectangle is a decent size to where the combination of all of the cuts likely won't add up to more than one width of a rectangle.

If it was an extra small part, it's very likely you'd lose a couple rows/columns.

 

[Hillbilly Deluxe]

OK so if I was to buy a full 4 ft. x 8 ft. sheet of 1/8 in. thick mild steel plate, how many 2 in. x 8 in. pieces could I get out of that?

Correct me if I'm wrong:

48 x 96 = 4608 square inches.

2 x 8 = 16 square inches.

4608 divided by 16 = 288.

So am I right? 288 pieces out of a full sheet?

I'd count on getting 253 pieces. That is 23 rows of 2" wide and 11 lengths of 8" long. That will allow waste.

Best to get it cut by a water jet. You're probably looking at $1k for all of this.

 

[y_p_w]

Shearing was mentioned, but I suppose there has to be some accounting for inaccurate sizing of the original piece and how much it might need to be deburred.

 

[Exhaustgases]

Keep us posted on how many you actually get, I suppose shearing is the only way not to have material loss cutting them.
I wonder if electron beam is possible? I know welding is with it.

 

[y_p_w]

Keep us posted on how many you actually get, I suppose shearing is the only way not to have material loss cutting them.
I wonder if electron beam is possible? I know welding is with it.

E-beam welding? Wasn't that used for the titanium wing box for the F-14?

I think of e-beam from my work, where we could take the top off an IC package, point an e-beam at it, and the reflection would be sampled in order to sample the state of a particular wire. Very expensive, but often the only way to failure analysis.