Stainless steel grade help

[brooker2008uk]

Hi i was wondering if someone can please give me some advice on stainless steel grades. i am looking to make a locking mechanism out of stainless steel which would be situated in an outdoor environment all year round.

Can someone please shed light and recommend a good common grade which would be good for machining, corrosion resistant and strength.

Many thanks in advance

 

[shed or dead]

Saw this in an earlier post today...

http://www.steelexpress.co.uk/non-ferrous/

I believe 304 or 316 will probably be best, depending on the harshness of the intended environment.

 

[TechnicAl]

If you live near the sea 316L maybe best, otherwise 304L as it should be cheaper

 

[brooker2008uk]

Ok thanks. If there is going to be no welding process would the 304l be good for machining

 

[shed or dead]

304 is easier to machine than 316 (so I'm told, never done it). Use plenty of coolant, and do not allow the work to overheat. Move the cutting tool at a good pace or the work may case harden from the tool rubbing on the surface.

 

[hotrodder]

304L can be nasty if you 'hit' it the wrong way as it'll then workharden creating a viscous circle. Basic rules covered here... http://www.aalco.co.uk/datasheets/Stainless-Steel_1.4307-304L_35.ashx Sharp tools, don't let them rub (positive feeds) etc as said and it machines nicely
303 machines beautifully (it's designed to) but as already mentioned in the link the trade off is lower corrosion resistance and toughness (mute point here but relatively nasty to weld as well)

 

[langy]

I would use 316, I machine it all the time and its nowhere near as hard to machine as some people would have you believe. cost difference is not much either.

 

[Lawnmowerboy]

304 is harder to machine than 316. 316 has silicon in which improves machinability. When cutting 316 it flows over the tool a lot easier.

 

[TechnicAl]

304 is harder to machine than 316. 316 has silicon in which improves machinability. When cutting 316 it flows over the tool a lot easier.

Who told you that?. Honestly mate, that is complete and utter rubbish.

as langy says there really isnt that much difference in machineability........as for cost I guess it depends on where and how much you buy. There should be around 20% difference based on steel mill pricing.

 

[Lawnmowerboy]

College. I'm more inclined to believe you than them. Our theory tutor has a geography degree and has never actually worked in engineering.

 

[Pete.]

304 is a cow for work hardening, worse than 316. If you're machining stainless find some 303 it's a whole lot easier.

 

[awemawson]

Just google 'machinabilty of stainless steels' there is a wealth of information out there. Key point is depth of cut - never let the tools rub or the surface work hardens to harder than a witches tit.

Andrew

 

[lshigham]

I had the misfortune to have to drill a load of holes in 304h with a battery drill, you really have to put some pressure on to get it to cut, if you don't it works hardens and bye bye drill bit

 

[TechnicAl]

304 is a cow for work hardening, worse than 316. If you're machining stainless find some 303 it's a whole lot easier.

303 is free machining / free cutting grade so it should be easier. Its loaded with Sulphur (maybe 10 X higher) which produces inclusions that act like perforations on a sheet of paper. Problems arise when you want to weld it or even bend / shape it.

 

[TechnicAl]

College. I'm more inclined to believe you than them. Our theory tutor has a geography degree and has never actually worked in engineering.

Sounds to me like he is getting it confused with Mr Sheen (Silicone Polish)...thats SILICONE with an E...........we are talking Silicon (the Element) which incidentally is present in most steels

 

[Lawnmowerboy]

I'll bring it up when I'm at college tomorrow and report back!!