Backing plates revisited/cutting stainless steel

[jimbouy]

Having scrounged some bits of stainless 316 ready to make up some new backing plates i have also got hold of some cobalt drills as rec. elswhere on the forum.

So next question is how am I going to cut to size.

Hacksaw? Jigsaw? Angle grinder?

Jimbouy

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[cindersailor]

Re: Backing plates revisited/cutting stainless ste

I find cutting straight in sheet material with a hacksaw very difficult, maybe there is some trick I do not know about, but once the blade drifts off the line there is no choice but to go with it! I have blunted many jigsaw blades in stainless steel, again, maybe I am using the wrong ones, but HSS does not seem to be up to it. I have recently bought some angle grinder cutting discs via ebay (see item number: 2491674182 for example ) these are only 1mm thick and seem very effective, although I have not used them very much yet. I think this is the way to go if you have an angle grinder.

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[richardandtracy]

Re: Backing plates revisited/cutting stainless ste

Stainless is VERY difficult, and HSS/carbon steel tools blunt very quickly.

If you don't mind heat discolouration, then cutting discs/ gas axe/ plasma cutters are the quickest & most effective ways of doing it. The next alternative that I'm starting to consider is a special purpose circular saw with metal cutting TCT blades (see MachineMart). They're in the region of £120, so I'll have to invent lots of jobs that just NEED it before I can justify one. Finally for small plates a bench shearer could be very good. However you'll be limited to 5" or so plate size.

Regards,

Richard.


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[davehu]

Re: Backing plates revisited/cutting stainless ste

Cutting stainless with a hacksaw is not difficult if you remeber a few basic rules. 1. get a good quality rigid hacksaw frame, 2. Get top quality blades, if its thin sheet get the maximum number of teeth. 3. Make sure the work is held firmly and that the hacksaw is held straight to the linbe of cut. 4. Work slowly, keep a steady pressure on the blade, sometimes a liitle light oil on the cut helps. Do do keep on work with a blunt blade as it will work harden the stainless and make it worse. Do not use and angle grinder, it will get the steel too hot and make it difficult to work again. When drilling, go slow but keep a good pressure on the drill, for holes of more than 3 mm you will need a drill stand to get the pressure. Hope this is useful

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[ROCKETSHIP_11]

Re: Backing plates revisited/cutting stainless ste

I use the s/s cutting discs all the time they are excellent good clean straight cut with little pressure ,
I fabricate in stainless steel for a living !!

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[Grandad]

jimbouy
Jig saw blades specifically for cutting SS are available by BOSCH. (At least from my local Engineering tool suppliers), BUT they retail at £33- for 3 blades.
Otherwise top quality Bi-metal blades at £7- for 5.
Agree with earlier posts on cutting, CUT SLOWLY with FIRM pressure and do not allow tools to rub, otherwise work hardening will occur.
Best of luck.
Bob


<hr width=100% size=1>Good judgement comes from experience. Most experience comes from bad judgement.

 

[starboard]

I cut stainless with a 115mm angle grinder fitted with one of the 1.4mm thick metal cutting disc. Theese ultra thin disc's slice through stainless as if it were butter. You can pick them up at most tool shops or screwfix direct about £1.20 each.

Paul.

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[jimbouy]

i'm going to try this type of disc in my angle grinder.

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[JerryHawkins]

I've successfully used a hacksaw with quality bi-metal blades with 32 tpi for cutting 4mm ss plate. The key is to keep it cool as it quickly work-hardens; as others have said. I used a hose pipe to flow water over the cut as I was going. If you see a colour change in the metal you've gone too quickly and you've had it!

I guess it took me about 20 minutes to make an 8" cut with a sinlge blade that was still in good condition at the end. So, not difficult, just time consuming.

Cheers, Jerry

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[andyball]

making holes

having tried cobalt drills on stainless, they're not always that clever,esp for holes over 6mm . ok, I'm no machinist & wasn't using a pillar drill, but anyway.

Axminster tools sell a set of stepped tin-coated cone-cutters for up to 5mm thick, & these are marvellous for stainless in my exp. I had to make some 12mm holes in 5mm s/s sheet for a seat mounting, and was dreading the job, (from previous experience).....it went really easily. Expected them to blunt in no time, but still ok & miles easier for me.

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[Mudplugger]

Re: making holes

Jim, I may be completely wrong, but I suspect that you want a degree of control over the size & shape of the pieces of S/S being cut...not impossible with up to 5mm thick with a decent power jig saw & metal blades PROVIDING you use an aerosol cutting fluid to keep the blade cool & lubricate the teeth and clear the swarf. If things like backing plates etc. may well be more accurate by hand, but again, use the aerosol.... In middle of building large bath tub! ..HTH Tony W.

<hr width=100% size=1>Tony W.

 

[jimbouy]

Re: making holes

If the angle grinding fails I'll try jigsaw.

Unfortunately that'll mean a new jigsaw as mine is on it's last legs.

Having said all this my surveyor seems to have been pre occupied with, "consider fitting larger backing plates"


Jim

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[yerffoeg]

A case can be made for using plywood instead of metal backers - wood will flex under pressure whereas stainless won't.

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[cameocrew]

I use normal HSS Tooling ( drills/hacksaws/jig saws etc.) with Molyslip MCC cutting
medium. Works a treat.

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[misterg]

Have successfully used electric jigsaw with decent bi-metal blade with fairly fine pitch (32 tpi??) available under Bosch brand at B&Q, etc. Lubrication is essential - I just used a squirt of engine oil on the cutting line every now and again. I also found it essential to cut at a slow speed (variable speed jig-saw). Cutting at full speed, or without oil = red-hot & blunt blade before cutting 10mm. Get it right, and I cut through about 5 foot of 2mm stainless without any aparent wear on the blade, and in reasonable time.

Other thought is to find someone with a plasma cutter - sounds exotic, but a lot of fabricators have them, and quite a few DIY car repairers. Not sure what sort of power you'd need, but will be quick, clean & allow you to cut whatever shapes you want.

Andy

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[ShipsWoofy]

I have used 1/2 inch polythene type sheet as backers on my mid cleats. They were offcuts from my replacement locker covers. All the virtues of ply without the rot.

I don't know if this is a long term solution, I often think about them when I put any strain on, but so far there is no sign of cracking on the deck. I have used very large washers so the weight should be spreading quite well.

I don't know if the 'give' they will have is a good idea, but it is much easier to work with than stainless plate. I would probably think twice before using them on main cleats, but only because it is against the norm.

oh, when trimming s/s on my foredeck I used an angle grinder, take it slow after cutting an initial guide groove and you can end up with a nice edge. Get a bastard file on while still hot and you can easily remove any burrs.

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>

 

[richardandtracy]

You did what with polythene?

I think you are possibly the first person to use polythene as a stuctural material. It is possible, but there are much better materials available.

Regards,

Richard.


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[ShipsWoofy]

I guess it is polythene or acrylic, it is softer than perspex. You can stand on my locker covers without any deformation. Where plywood might splinter this material will give slightly.

We are not talking polythene bags here, this stuff is strong and durable. I see very little difference between this and plywood backing, other than it wont rot.

I did say I am watching it and do have reservations, but so far there has been no problem, they have been subject to snatch loads and survived. My vessel weighs in at 3 tonnes, we are not talking 10 tonnes of yacht here.

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>

 

[ongolo]

Re: making holes

I am amzed htat you people are not aware of products such as tap-all or tap-easy.

They are amixture of a very light oil and an evaporating agent. I am not quite sure what the evaporating agent is, it evaporates like acetone but is not flammable.

While cutting ot drilling at normal speed and normal drills, you spout a thin stream (from its provided dispenser) continously onto the tool/work piece. The liquid evaporates and literally boils away at 50 or 60 Cel I would guess. That keeps the SS ice cold and no workhardening occurs.

But 250ml cost here GBP6,- and that is bloody expensive for Africa.

regards ongolo,

yes I am alive and will post my story soon


<hr width=100% size=1>Nothing shall surprise me again, not even when my male dog billy should become a lesbien tomorrow

 

[Strathglass]

As has been stated earlier the grinder is the way to go.

I have found that 1mm grinder disks specifically for stainless are available from several sources.

They cut very easily but you will still have to remove the rag.

I have used them to cut everything from 1mm to 10mm sheet and even cut 1" tubing.
It is possible to use a jigsaw or hacksaw but lubrication is required.

Iain

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