Is RSJ Steel machinable?

[Ace ChandlerParticipant @acechandler49785]

Our conservatory is being replaced – it has 3 large RSJ's that came out of the old one that are now surplus to requirements.

It seems a shame to scrap them. I don't have an immediate "construction" use for them, but was considering hacking them up with an angle grinder and storing the steel for use with general machining.

I don't know if they are in the category of things like Rebar which I beleive as being well documented as terrible/horrible to machine.

So basic question is does RSJ Steel machine/weld well?

Thanks, Ace

[Ace ChandlerParticipant @acechandler49785]

[JasonBModerator @jasonb]

Welds well and is reasonable to machine if a littly gummy.

This part was cut from the other corner that made up a steel channel

[Andrew TinsleyParticipant @andrewtinsley63637]

Never had any real problems machining RSJ material. If you have the space, keep it, you will find a use for it.

Andrew.

[Nick WheelerParticipant @nickwheeler]

It cuts, drills and files well.

Cutting up RSJs just to keep the steel is daft. It's much more likely to be of use in long lengths.

[Martin KyteParticipant @martinkyte99762]

Certainly will not be free cutting as it's weldable.

regards Martin

[larry phelan 1Participant @larryphelan1]

Cut it up only as you need it ! Much better left in lengths.

[Dave HalfordParticipant @davehalford22513]

The RSJ are worth money as is chopped up they are not, a 5 x 3 rsj is £25 per M

[SamsarandaParticipant @samsaranda]

When we refurbished our bathroom there was an RSJ spanning the bathroom under the floorboards and we needed to route some pipes through it so used a standard hole saw in an electric drill, with a bit of oil to aid cutting, and it was no problem it cut easily. I wouldn’t hesitate to use it for projects. Dave W

[old martParticipant @oldmart]

It machines ok, I used an offcut for a vise modification.

Some people would love some to mount their lathe on to increase the mass.

Edited By old mart on 24/03/2021 15:00:13

[SillyOldDufferModerator @sillyoldduffer]

Should be machinable but it does depend rather on what steel a particular RSJ is made of. They're not all the same.

Usually RSJs are made of a mild-steel plus a dollop of Manganese for extra strength. EN3 is similar but weaker and an older RSJ may have been made from it. Modern RSJs are tougher, but still machinable, OK rather than good.

High-specification RSJs are sometimes made of exotic steels which might not machine well, but the chances of anything special coming out of a demolished conservatory is low!

Try it and see. I think it'll be fine.

Dave

[Sam Longley 1Participant @samlongley1]

My Warco lathe & M16 Mill both sit on standard Warco cabinets. 3 short lengths under the lathe cabinet & 2 under the mill cabinet raising them both 9 inches makes a h..ll of a difference to one's back after a couple of hours playing at either ( i am 6 ft 6ins tall) . Easy to bolt to the floor & to the cabinets & no flexing.

[noel shelleyParticipant @noelshelley55608]

RSJs are worth good money and there is a ready market for them. A 6 or 8' length will make a mighty fine wood splitter. Cutting it up would be tiresome. Noel.

[duncan webster 1Participant @duncanwebster1]

RSJs are made from BS EN 10025 S275. The 275 refers to it's yield stress which is 275 N/mm^2. It welds well and machines reasonably, although it wouldn't be my 'go to' choice.

Put it on Ebay, someone might be building an extension near you

[DC31kParticipant @dc31k]

Posted by SillyOldDuffer on 24/03/2021 17:31:18:

High-specification RSJs are sometimes made of exotic steels…

Could you give an example please of a 'high specification RSJ' and while you are at it, please give an example of a low or normal specification one just so we understand the distinction you are trying to make.

Structural steel will be either S275 or S355, properties for which, including machinability, will be easily found with the aid of a nearby Google.

[Roger BestParticipant @rogerbest89007]

I had a hell of a job drilling holes in an RSJ for my house. 275 is proper strong stuff and the cheap drills didn't like it.

Sell for its proper use and buy something useful I say.

I had a beam outside for a decade. A good coat of red oxide and bitumastic paint kept it in good condition.

[noel shelleyParticipant @noelshelley55608]

Drilling holes in RSJ is what mag drills and rotabroaches are for ! A joy to use for almost any size. Noel.

[DiogenesIIParticipant @diogenesii]

They'd make the basis for a useful hydraulic press if you add a cheap bottle-jack and a couple of bits of angle..

[SillyOldDufferModerator @sillyoldduffer]

Posted by DC31k on 24/03/2021 19:14:45:

Posted by SillyOldDuffer on 24/03/2021 17:31:18:

High-specification RSJs are sometimes made of exotic steels…

Could you give an example please of a 'high specification RSJ' and while you are at it, please give an example of a low or normal specification one just so we understand the distinction you are trying to make.

Structural steel will be either S275 or S355, properties for which, including machinability, will be easily found with the aid of a nearby Google.

Certainly!

As RSJs were being rolled long before S275 existed, a joist recovered from an old building might not be made of it. Not unlikely to be something similar but it could a plain carbon mild-steel. Bessemer didn't know about Manganese, and as adding it puts the price up, ordinary mild has been rolled as a structural steel. Pre-war British structural steel wasn't made to a standard at all – it varied by maker. Counterfeiting is another possibility.

At the 'better' end, I first heard of Nickel-steel RSJs being used in shipbuilding to save weight. Strong alloys are used in super-towers for the same reason. Like railway lines, they are made to order but stainless steel RSJs can be had for more ordinary purposes.

The comment came from my bad early experience with scrap, explained when I twigged there are thousands of different alloys out there, and many don't machine well. Unknown metals should be tested because it's unwise to assume anything. Great if scrap works, just be aware should trouble occur that not all metals machine well. The answer to 'Is RSJ steel machinable' is probably yes, but it has to be tried to prove it.

Dave

[Nigel Graham 2Participant @nigelgraham2]

The beans you have would probably machine satisfactorily, and weld easily, but it is a gamble.

I have used off-cuts and scrap-yard pieces of hot-rolled sections and plate for various things without too much trouble – the worst I recall was that used years back for bed-frames. (Our club went through a phase of using those for all sorts of projects, and some of the frames were scavenged from fly-tips in local quarries!)

Really, for the amount of metal you are likely to use from your RSJs, and the number of cutting discs expended cutting them into bits, it would be better to sell them as serviceable building components, and keep the cash for buying known steel to appropriate sizes as and when you need it.

[HopperParticipant @hopper]

Drill a hole in it and see for yourself how it machines. If good, keep it. If bad, flog it off.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Nigel Graham 2 on 24/03/2021 23:01:42: …

– the worst I recall was that used years back for bed-frames.

…

Me too!

Was told many bed-frames were rolled from scrap tram-lines lifted between 1930 and 1950 as motor buses replaced them almost everywhere. Makes sense because tram and railways lines are both made from a particularly tough hard-wearing Manganese Steel designed to give many years service, and the tram out, bed frame in, timing is right. Whatever old bed-frames are made from, it's not mild-steel!

Although tough when cold, hot rails are easily re-rolled and hole punched so bed-frames could easily be made from them. However rail metal is a pig to machine, and the lengths of bed angle I have are uncooperative. A few inches of railway line is tough enough to make a decent anvil!

Dave

 

Edited By SillyOldDuffer on 25/03/2021 10:10:52

[WindyParticipant @windy30762]

Posted by SillyOldDuffer on 25/03/2021 10:10:38:

Was told many bed-frames were rolled from scrap tram-lines lifted between 1930 and 1950 as motor buses replaced them almost everywhere. Makes sense because tram and railways lines are both made from a particularly tough hard-wearing Manganese Steel designed to give many years service, and the tram out, bed frame in, timing is right. Whatever old bed-frames are made from, it's not mild-steel!

Edited By SillyOldDuffer on 25/03/2021 10:10:52

Those old tram lines were used for many jobs not far from me the curved edging on a road junction is made from tram lines.

Was talking to a person who installed them when he worked for York Council years ago.

The Council were short of road edging so there blacksmith would bend the disused tram lines to suit the curve required.

You can still make out the markings on them.

[mark costello 1Participant @markcostello1]

Bed rails were probably impact hardened several different ways.

[Nigel McBurney 1Participant @nigelmcburney1]

Most bits of rsj I have come across,machines similar to common black iron,ok for brackets,and a good support under a lathe,my myford sits on a length of 7 x 3 channel. and welds ok. As others have said dont cut it up,at least keep a length as you might need a lifting beam in your garage some time in the future,give it a coat of red oxide, As i understand it ,if regulations are complied with steel used in buildings must be new for some time,more recently structural steel in buildings ,has now to comply to an ISO spec and its origins traceable. The thin light angle iron used years ago for bed frames is very strong,Back in the 60s I used some to make trailer,borrowed the works gas welder,the angle spit and spluttered and flakes came off it ,then I found it brazed ok, Hacksaw blades did not last long,no angle grinders in those days. I aquired a supply of more bed angle a while ago and used it to make security bars for shed windows, Going back to machinability of rsjs, i aquired some heavy angle and channel which was galvanised and used by the electricity board for supporting pole mounted tramsformers,now that machine a easily as bright mild steel,there are a nuber of long slots for bolts so perhaps a better steel was specified as they would need an awful lot of steel

[Author]

Posts