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By rafezetter
#1292376
I've got some strap hinges and the pins seem a little malleable. I've not put the weight on them to check (there are 4 total), but if it turns out they bend under the weight as they are being used horizontally to support the wheels on a heavy workbench, is straightening them and hardening them a possibility?

Anyone done this?

I'm limited for space otherwise I'd have used beefier ones.
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By Trevanion
#1292377
It really depends whether it’s a high carbon steel or not, there’s no real way of telling exactly what steel grade it is but you can get a rough idea of whether it’s mild or high carbon by performing a spark test.

If you’ve confirmed it is indeed some form of high carbon steel there isn’t really anything stopping you from giving hardening and tempering it a go, provided you’ve got good enough gear to do it. A MAPP torch isn’t really good enough to keep the heat up anything longer than say an inch in 5mm stock but if you’ve got better all the power to you.

If the steel isn’t hardenable and you don’t want to buy new hinges you can pick up hardened steel rods/dowel/pin stock online fairly inexpensively, probably cheap enough that it wouldn’t be worth the hassle of hardening them yourself!
By sunnybob
#1292378
Are you using castors that are strong enough? every castor has a rated wight limit. work out the ALL UP weight of the bench and contents and divide by however many castors you have. If youve used under rated castors, youre in dangerous territory. Rubber wheels will flatten and stop the wheels turning. Solid wheels could shatter.
If the castors are rated correctly you have nothing to fear.
By AES
#1292432
I think the above observation is most likely, but if you are really worried, find a Model Engineering supplier near you (suppliers sticky at top) and buy yourself a length of silver steel of the appropriate dia. Very hard/almost unbendable, ground very accurately to roundness and specified diameter.

Comes in 13 inch lengths (don't ask me why - but just FYI, same as standard raw spaghetti lengths)! Oh yeah, for Inspector (above) and others over the pond, called "drill rod" over there.
By Inspector
#1292440
13" = a one metre length cut in 3.
Silver steel = drill rod. I knew that just like I know how to spell metre when dealing with you and meter when talking to those South of me. ;)

Pete
By rafezetter
#1292442
Thanks for all the replies - replacing the pin seems a better idea, but the "peeling open" part does have me a little concerned.

Sunnybob the castors are rated for 160kg EACH, so even though it's pretty beefy I can still pick it up by the ends, but ty for checking.

If it's not high carbon steel is there any point in trying to harden the area around the pin, is there no gain to be had at all?
By sunnybob
#1292446
Assuming the casters are rated at 160 kg each, and you have 4 of them, then they will hold an all up weight of 480kg comfortably and safely.

Thats a 1014 lbs. Which is near as dammit a half ton (imperial). I dont see any reason to fret over the wheel spindles.
By TFrench
#1292525
AES wrote: Oh yeah, for Inspector (above) and others over the pond, called "drill rod" over there.


Thanks for that, I never knew thats what all the youtubers I watch were talking about! :D