Bright steel and free machining

[morrisman]

Hi

Just wondering what most of you prefer for general machining . The generic term BMS actually means a few different grades of steel . Ideally the 12L14 or similar free machining grades are what I would like, but that stuff is just not avialable around here , the local merchant only has the horrid black stuff . Are the other grades of BMS - 1020 etc OK ?

Is there anywhere the 12l stuff is available on the eastern side of Melbourne ?

[Big Shed]

http://www.buau.com.au/131.php

They are in Greens Rd Dandenong.

I used to get my 12L14 from their Bayswater branch but that has been closed, they cut to length there. Have bought anything up to 75mm diameter.

[morrisman]

Fred ............. i did go to that company a few years ago but they said I have to pre order and it takes weeks to get the stuff down from sydney , a strange attitude I thought . ??????????? mike

[Big Shed]

At their Bayswater branch I used to ring them the day before just to check they had stock, then waltz in the next day and tell them I wanted a meter of this and a couple of meters of that, they would cut it whilst I watched and waited.

Never been to the Dandenong HO so I wouldn't know about them. My local steel merchant only has the 1020 variety of BMS, have used it but I far prefer the 1214 stuff.

I used to get a lot of 1214 bar ends from a CNC machining place. They can't use the end of the bars in their automatic feeds. Unfortunately the guy I used to get them from has left and the new bloke is not very amenable to a bribe of a bullet pen or two.:no: Used to get a fair bit of hex stuff as well as brass.

Maybe see if there are some CNC places in your neck of the woods?

Failing that, have you looked at 303/304 Stainless bar, quite easy to machine once you get used to it, I now use a lot of it and can get a very good finish on it with HSS. Costs a bit more though.

[PDW]

Failing that, have you looked at 303/304 Stainless bar, quite easy to machine once you get used to it, I now use a lot of it and can get a very good finish on it with HSS. Costs a bit more though.

303 is beautiful to machine, 304 is another story altogether - it can be machined to a nice finish, but you better not play with it and try to scratch little cuts off it. I avoid 304, much rather machine 316L if 303 won't do.

Yeah it costs more. A lot more......

PDW

[.RC.]

I was under the impression Bright Mild Steel was just a term for mild steel with a bright finish, as opposed to a black finish..

[Big Shed]

The black is hot finished the bright is cold finished.

Black is K1045, BMS is 1020, 1020,1030,1045 and 1214, see my link above, there are pdf files to download there as well.

[Big Shed]

303 is beautiful to machine, 304 is another story altogether - it can be machined to a nice finish, but you better not play with it and try to scratch little cuts off it. I avoid 304, much rather machine 316L if 303 won't do.

Yeah it costs more. A lot more......

PDW

In my experience, and this is backed up by the spec sheets on the Interlloy website, 303 is the easiest, followed by 304 and 316 is the hardest to machine of the 3. YMMV.

I turn and drill both 303 and 304 and you are right 303 is the easier to machine of these 2, but I don't like 316:no:

With the drilling of these the thing is not to stop as it work hardens very quickly.

[nearnexus]

The black is hot finished the bright is cold finished.

Black is K1045, BMS is 1020, 1020,1030,1045 and 1214, see my link above, there are pdf files to download there as well.

I've got a big hunk of 1040 round stock - really nice to machine.

Do they still do that one?

Rob

[malb]

In my experience, and this is backed up by the spec sheets on the Interlloy website, 303 is the easiest, followed by 304 and 316 is the hardest to machine of the 3. YMMV.

I turn and drill both 303 and 304 and you are right 303 is the easier to machine of these 2, but I don't like 316:no:

With the drilling of these the thing is not to stop as it work hardens very quickly.

Used to machine a lot of SS materials, and the source of the material is as critical as the variety. The Swedish stuff from Fagursta was always miles better than any generic Chinese stuff of nominally similar grade because the Chinese stuff had inclusions all the way through while the Swedish stuff was homononous. Fag 316 was generally more reliable to drill and tap than the supposed free machining 303 from China.

[PDW]

In my experience, and this is backed up by the spec sheets on the Interlloy website, 303 is the easiest, followed by 304 and 316 is the hardest to machine of the 3. YMMV.

I turn and drill both 303 and 304 and you are right 303 is the easier to machine of these 2, but I don't like 316:no:

With the drilling of these the thing is not to stop as it work hardens very quickly.

Odd because I find that 304 is a lot worse to deal with than 316. But then I've used an awful lot of 316 on the boat so I know just how it behaves and I have a set of tools ground to suit. I don't use a lot of 303, in fact I prefer not to have it about the place, because it's contra-indicated for welding and I have done a lot of stainless welding then machining afterwards - solid bar into pipe ends then machined concentric with keyways etc, the idea being to keep the weight down.

A good habit to get into is to write on the ends of all bars what they are - I use a Pentel pen as soon as I bring the stuff home, and cut off the unmarked end.

I agree completely about the drilling, except to say don't let the bit rub. It's ok to stop drilling if you retract immediately to apply more lube (peck drilling) but if the bit gets blunt and starts rubbing, forget it. Also use a fair bit of pressure and a reasonably slow speed. Playing with it doesn't work. I have melted good HSS drill bits by trying to push a blunt drill. It's no fun trying to finish the hole from the opposite side.

PDW