Recent content by mschro

Hi, We have a shear shredder operating in a difficult application where it is shredding mild steel with a somewhat thin cross-section (3/16" minus). The cutters in the shredder are general purpose blades made from 4140 heat treated to 52-55 RC. The blades are seeing both rapid wear and...

We build a lot of heavy equipment for which we design lift lugs. I have been told that the hole that a shackle goes through for lifting should be 'drilled' versus 'burned out/plasma' cut. Is there any code that supports this, or is a plasma cut hole acceptable?

Thanks FACS. This 10' long tube that the product is passing thru attaches to a flange/nozzle. Our customer is supplying this nozzle and is concerned about the loads that it will be subjected to. The screw is creating a rotating load into the column of material that is compacting within the...

I have a feed screw that is conveying material and then forcing it into a discharge tube. The bulk density of the product is 15 lb/ft^3 when it enters the discharge tube and 50 lb/ft^3 when it exits. The discharge tube is made from 316 ss and is 10 feet long (20 inches in diameter). If I can...

I want to fabricate an auger screw out of two dissimilar materials. Normally we use an SAE 8620 hot rolled material for the shaft and an 8620 casting for the flight. In this process we preheat the shaft to 400-500 deg F prior to welding the flights to the shaft. We now have a very severe...

We make a fabrication of an auger that consists of welding a cast 8620 flight to a 8620 steel shaft. We are having a difficult time meeting our delivery requirements based on the lead times for the cast flights. A foundry we talked to suggested we use a 80-60-03 ductile cast iron as a...

We manufacture the screw extruder ourselves. In our other applications until now, a low melting point of the material being processed has not been a problem. We are committed to a design as described above. I guess I was hoping someone had run across a similar type scenario and could guide...

That's a good suggestion, but in this case the material can't have anything added to it.

The flight is about 300 deg F

I have a screw type extruder that heats up from the friction of the material being processed. Some of the material being processed has a low melting point. I want to cool the last flight of the screw extruder enough that the temperature at the end of the extruder remains below the melting...

Thanks corypad, The thought with the double washer was to add stiffness and avoid (reduce) any deflection of the washer above a oversized hole.

Thanks to everyone for their feedback. dimjim (and others with an opinion), I was a little concerned about the bearing pressure under the washer as well. I'm not sure how to best analyze this. Do you have any recommendations? My initial thought when presented with the situation was to stack...

I have an application where a flanged shaft is bolted to the rotating flange on a hydraulic motor. The bolts being used are gr12.9 - M24's and torqued to 664 ft-lbs (lubricated with loctite). The motor is threaded, so the bolt with a narrow washer (against the bolt head) goes through the...

So, based on what prex said, and based on the Italian code, the surface finish can have a very large impact. Correct?

Any idea on the percentage gained by the change in surface finish. Are we talking a couple percent difference, or could it be 10% (or greater) difference? Thanks