Will Stainless bar bend or will it snap?

[billwill]

Does anyone know whether Stainless Steel flat bar Grade 304 will bend like mild steel, or is it brittle and will snap?

[rgh0]

304 is a relatively ductile stainless and will bend to some degree. However it does work harden so large bends and repeated bending can cause cracking. If doing a big bend I would heat with a torch first

cheers
Rohan

[billwill]

I've ordered some 40mmx5mm Grade 304 bar to make some garage door hinges. I was planning on 90 degree bends to make wide U brackets |___________| then I realised it might not bend

[gus]

I would use 303 as 304 is terrible to drill

[RichardHawkins]

Bill,

As Rohan says, it work hardens, but can be drilled. You need a sharp drill and sufficient force to keep that drill cutting, don't let the drill rub or the 304 will harden and become very difficult to cut.

Richard Hawkins

[UAB807F]

It will bend ok, but 5mm is quite thick and you'll need some effort to get it into a sharp 90deg bend. As has been mentioned work hardening is a problem and that's usually how the average DIY'er manages to ruin his drills. (and yep, that includes me even though I ought to know better )

It's austentic structure so that makes it quite tough, hence being used at cryogenic temperatures where mild steel is brittle and snaps. The proper hot working temperatures are around 1000C (I forget exactly) but even so I think I'd be tempted to warm it up before trying to bend 5mm steel.

Brian

[billwill]

I have one of these to do the actual bending.



http://www.sealey.co.uk/PLPageBuilder.a ... results=16

[billwill]

Aw heck, just realised I miscalculated the order and have ordered only 1 metre of stainless steel bar and will need nearly 2 metres altogether. And that's the slowest of the suppliers too.

Oh well, that give the the chance to use just plain mild steel bar for the brackets that will be out of the rain on the in-side of the garage doors. Should be easier to drill..

[UAB807F]

That's a neat piece of kit Bill, I can see you've moved on from the "clamp in a vice and hit hard" method !

Can you get galvanised steel ? That's what most hinges on our gates are made from, easy to drill new holes in and of course it doesn't rust so easily.

[billwill]

I bought the bender a few years ago, when the people I bought 'wrought-iron' railings from said they were unwilling to make the particular shaped footings that I needed.

Rail footings, before final bend and paint.

Complicated rail footings

~~~~~~~~~~~~~~~~~

Pre-galvanised stock steel does not seem to be readily available. I did think of galvanising but I don't know of any readily accessible galvanising firm near here.

Some of the parts I've bought to make the hinges are gate parts and are galvanised.



I may have 'over-engineered' these garage door hinges, as I bought 20mm versions of these eye bolts and studding (they feel massive) so I have to drill lots of 20 mm holes in the stainless steel. Probably 10mm or 12mm would have been adequate (snd cheaper)

[reb53]

"I bought the bender a few years ago, when the people I bought 'wrought-iron' railings from said they were unwilling to make the particular shaped footings that I needed."

As the inverted commas suggest, wrought iron hasn't been around for years.
All the so called "wrought iron" that is sold is actually mild steel, that unlike wrought iron, rusts.
Maybe there's one in China or somewhere, but I seem to remember the last puddling furnace, used to make real wrought iron, went out of existence in the UK about 100 years ago.

[billwill]

Yes Indeed...

And painting it all with white Hammerite is a right pain...

[billwill]

It proved impractical to work the stainless steel; My 1/3 HP Chinese Pillar Drill was incapable of drilling 20mm holes in the stainless bar.

In the end I opted for Aluminium flat bar and have now created all the adjustable hinges and with the muscles of a friend have mounted the new wooden garage doors.

I cut the old metal up&over door into two halves with an angle grinder and took them and the sawn up former door frame up to the recycling 'dump' yesterday. In two halves it only just fitted in my Grand Espace MPV with the passenger seat as far forward as possible, but that did save the effort of cutting it into quarters.