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Hello, I am looking to fabricate a lift device for use in cold weather (down to -45C). Aluminum 6061-T6 appears to be acceptable from the information I have, -45 will only make aluminum stronger (do not need to worry about brittleness like with steel). Anyone have any knowledge of Aluminum...

Thanks for your reply, I will look into these

Does anyone know what standard tow bars need to be designed to? I am having trouble finding this. Thank you

Thank you all for your replies!

Thank you everyone for replying. I have attached sketch of a hypothetical case. My question is more just in general: would you use a ratchet strap as the primary lifting support for overhead lifting? Instead of slings or wire rope or chain? Assume ideal conditions: safe WLL, lifting rarely, wear...

Would you use a ratchet strap for lifting? Incorporated into a lift device?

Thank you everyone for your replies!

Hello, Does anyone know the drag force calculation and drag coefficient of a hollow rectangular shape? Thankshttps://files.engineering.com/getfile.aspx?folder=a8fd8920-e423-4ce9-b424-efc1ec89f51c&file=Drag.pdf

Thank you everyone for your replies. MintJulep: that standard does not have design factors that I can see, only proof loads for testing (so at max, SF=2) ANSI ALCTV for automotive lifts uses SF=3 to ultimate strength

Thank you for your replies, I feel satisfied with minimum SF 5 now. LittleInch: by holding a load I mean for example an automotive hoist or a pair of stands holding up a larger vehicle where people need to be underneath to perform maintenance.

Thank you for your replies, I use SF=3 for general purpose spreader bars (From ASME BTH category B lifter, service class 0) For manbaskets I use SF=5 (From CSA Z150) So I usually use SF=5 for people underneath a load because the same risk is involved for a manbasket. But I have noticed others...

What design safety factor do you use for equipment holding a load where people will be working underneath? Thank you, A.M.

Thank you everyone for replying, makes sense now.

Hello, I am designing a tie rod for a wall mounted jib crane. I have attached a Spanco drawing of a similar design. My question is: do I need to make room for a wrench for the nut that sits between the tie rod clevis plates? Or is it just hand tightened during the adjustments during install...

BTH-1 states that there must be two bolts per bolted connection (3-3.2 Bolted Connections). However, crosby sells swivel hoist rings and other lift tools that are only one bolt for the connection. Can anyone explain the difference here? Thanks.

For "3-2.4 Combined Axial and Bending Streses" in BTH-1-2008: I am being told that when fa/Fa>0.15, I can still just use equation (3-31) instead of (3-29)/(3-30), that (3-29)/(3-30) are optional. The way I read it is that you can only use (3-31) if fa/Fa<0.15. Does anyone have experience with...

Thanks for the replys! IRstuff: I used the formulas they gave to calculate the maximum load on the wheel based on the 4420 psi allowable bearing stress of the concrete. BigH: I have read through the thread but I did not see a solution, structSU10 had the same question I had about this formula...

Does anyone know how to design for the bearing stress of a steel wheel on concrete? I found this article online: http://www.burnsmcd.com/insightsnews/insights/tech-briefs/2011-issue-1/contact-mechanics But according to this article, a 6" diameter x 3" wheel can only carry about 140 lb on...