huangyhg

manual chain hoist load rating
we need to rate some small manual chain hoist ,these are used to lift material and various small parts, what is the fs required by osha.
if i recall, osha publishes this on the website. in general, i recall for rigging it was 4 or 5 fs on wire rope, hooks, blocks, etc.
i take it you're in the states somewhere. in alberta, canada, there isn't a required safety factor or standard for lifting devices with a capacity of less than 2000 kg- it simply must be certified by a professional engineer. check your osha legislation though.
for reference, rigging safety factors (rope, slings, shackles, etc...) are 4-5, below the hook devices (spreader beams, etc...) sfs are a minimum of 3 (see asme b30.20 & bth-1) while cranes can be as low as 1.5-2.5. i would aim towards 3-4 as chain hoists are typically neglected as far as maintenance and inspection.
if people can stand underneath the load, or it is man rated, then higher sfs apply, where i work we design to 4 and test to 2 annually, for general workshop hoists and jibs.
cheers
greg locock
check w/ the mfg. ropes, slings, etc are 5:1
every piece of rigging/literature from a manufacturer states that persons should not be under the load. nobody wants this liability...
i doubt you're lifting people with a manual chain hoist but the required safety factor here for manlifts is 10:1.

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