phelpsa
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| posted on 21/6/16 at 01:22 PM |
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Custom bracket manufacture
Looking to get some custom suspension brackets cut and folded from 2mm s355, any recommendations for places set up to do this reasonably cheaply? Qty
about 20.
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coozer
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| posted on 21/6/16 at 02:32 PM |
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Best to use a hole saw, drill and reamer and make them out of box section.
1972 V8 Jago
1980 Z750
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phelpsa
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| posted on 21/6/16 at 02:42 PM |
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quote:
Originally posted by coozer
Best to use a hole saw, drill and reamer and make them out of box section.
Interesting thought, got any suppliers of 25x30x2 rhs in S355?
Not really too bothered how they're made as long as they're to design.
[Edited on 21-6-16 by phelpsa]
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liam.mccaffrey
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| posted on 21/6/16 at 03:26 PM |
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have you had a problem in this area strength wise, I'd have thought that s275 would be more than adequate.
Is it a weight thing, or allowable stress?
EDIT
That sounds like im trolling, im really not just curious 
I don't think you can get S355 in RHS
[Edited on 21/6/16 by liam.mccaffrey]
[Edited on 21/6/16 by liam.mccaffrey]
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phelpsa
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| posted on 21/6/16 at 03:37 PM |
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quote:
Originally posted by liam.mccaffrey
have you had a problem in this area strength wise, I'd have thought that s275 would be more than adequate.
Is it a weight thing, or allowable stress?
EDIT
That sounds like im trolling, im really not just curious
[Edited on 21/6/16 by liam.mccaffrey]
Going racy on bearing sizes, just want the strongest I can get while still being mig-able really! 275 would probably be fine, but might as well go
from 355 if I can. Less risk of damaging the bracketry in a shunt too...
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phelpsa
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| posted on 21/6/16 at 07:35 PM |
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quote:
Originally posted by liam.mccaffrey
have you had a problem in this area strength wise, I'd have thought that s275 would be more than adequate.
Is it a weight thing, or allowable stress?
EDIT
That sounds like im trolling, im really not just curious
I don't think you can get S355 in RHS
[Edited on 21/6/16 by liam.mccaffrey]
[Edited on 21/6/16 by liam.mccaffrey]
Found a place that does S355 25x50x2mm, trying to find out minimum quantity.
They do S420 as well, dont know much about it, any ideas if its mig-able?
[Edited on 21-6-16 by phelpsa]
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mcerd1
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| posted on 22/6/16 at 08:36 AM |
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If your going to this effort I hope your specifying 'hot finished' hollow sections rather than the 'cold formed' poo ? 
hot finished sections have tighter corner radii and far less residual stresses (cold formed sections can have issues when you weld on the
corners...)
hot and cold hollow sections are both made from the same grades, hot is done to EN 10210 and cold to EN 10219
Also the 'sub grade' of the steel states its minimum impact toughness - for hollow sections J2H is the commonly available one and pretty
decent (J0H would be fine too, K2, NH and NLH are far better than you'll need for 2mm thick steel), but don't let them fob you off with
some nasty untested poo 
so the correct/complete designation for the steel grade should be: "EN 10210-S355J2H"
also it should have the mill test certificate avalible for the batch it came from, one like this - the formating does vary a bit, but the
'3.1' type certificate allows it to be CE marked too (a legal requirement for lots of things these days, but it means its properly tested
and traceable)
http://www.steelconstruction.info/images/thumb/5/5c/Tata_Steel_DOP.png/600px-Tata_Steel_DOP.png
S355 obviously has a higher yield strength than S275 and a higher bearing strength too (i.e. its resistance to ovaling the holes)
but it is a little more brittle and also has less capacity to ignore small holes etc in its strength calculations than S275 (overall it still works
out stronger, but the design has less room for error, S460 is even worse and requires you to allow for every tiny hole no matter how small)
in structural steelwork (what these steels are designed for - hense the 'S' in the grade ) the common grades are S235 (European mild),
S275 (British and sometimes Dutch mild), S355 (high yield) and S460.
S235 tends to be cheap and available for light sections especially cold formed hollow sections, but we tend to ignore it and just use S275 or S355 in
the UK
--------
S235, S275, S355 and S460 can all be welded with the same wire, however the weld will only be as strong as the weakest part (i'm counting the
weld itself as a part too)
the wire classifications I use when designing these are:
class 35 = yield: 355, tensile: 440, min elongation: 22% - meant for S275 steel gives 220N/mm² weld strength
class 42 = yield: 420, tensile: 500, min elongation: 20% - meant for S355 steel gives upto 250N/mm² weld strength
class 50 = yield: 500, tensile: 560, min elongation: 18% - meant for S460 steel gives upto 280N/mm² weld strength
(
so for example if you weld an S355 bracket to an S275 chassis - you can use either a class 35 or class 42 electrode (aka wire), but you'll only
get a weld strength the same as if everything was S275
or you could make all the steel from S355 but weld it with a class 35 electrode and you'd only get an weld strength equivalent to S275 steel
we use a mix of S275 and S355 steel and use a class 42 wire for everything (BS EN ISO 14341: G3 Si1) - like this one:
linky
[edit] - wow that's a bit more than I meant to type 
[Edited on 22/6/2016 by mcerd1]
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phelpsa
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| posted on 22/6/16 at 09:37 AM |
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Excellent info! Thanks for taking the time.
That's the exact standard definition they have given. The weld area is massive but the bearing area is the concern.
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Neville Jones
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| posted on 22/6/16 at 09:51 AM |
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50 for £75 at my local laser cutter/sheet metal place. You provide the material.
You should know what you're doing, in your line of work, but thinning suspension brackets brings its own problems. I've done them from
1.5mm high tensile in the past,...and replaced them. They'll need to be lifed.
[Edited on 22/6/16 by Neville Jones]
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phelpsa
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| posted on 22/6/16 at 10:28 AM |
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quote:
Originally posted by Neville Jones
50 for £75 at my local laser cutter/sheet metal place. You provide the material.
You should know what you're doing, in your line of work, but thinning suspension brackets brings its own problems. I've done them from
1.5mm high tensile in the past,...and replaced them. They'll need to be lifed.
[Edited on 22/6/16 by Neville Jones]
This post would be more use if you gave me the details That's the sort of deal I'm after. I presume that's IOW local rather than
Oz local? The places local to me that I've tried have had minimum order between £500 and £1000.
Thanks for the advice, where did you suffer the failures? None of the loads I'm looking at are anywhere near high enough to trouble the 2mm
brackets. I've instron tested the same design made from 4130 to 25Kn tensile which is about 10x the maximum load and 30x the running load. My
only slight concern being the bearing load should a bolt loosen.
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Neville Jones
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| posted on 22/6/16 at 05:00 PM |
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Try Island Sheet Metal.
I'm a regular customer, so get good rates.
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lsdweb
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| posted on 23/6/16 at 07:24 AM |
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Trident Engineering (Welsh Championship sponsors)?
Try Griff - http://www.trident-engineering.wales/
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phelpsa
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| posted on 23/6/16 at 08:09 AM |
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quote:
Originally posted by lsdweb
Trident Engineering (Welsh Championship sponsors)?
Try Griff - http://www.trident-engineering.wales/
Will give him a call  thanks Wyn!
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