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Member postings for David Jupp

Here is a list of all the postings David Jupp has made in our forums. Click on a thread name to jump to the thread.

Thread: Hardening Stainless Steel
16/01/2013 19:21:25

Was not suggesting work hardening as a method to use (it explains why so many drills get broken in stainless) - just pointing out that 300 series steels will not harden by quenching.

If you want to harden stainless, it has to be from the correct family - if it is strongly magnetic you have a good chance it is. If weakly magnetic it's probably only workhardened austenic steel so will not quench harden.

16/01/2013 18:44:42

I can't see some of the posts becuase they are obsucred by the advertising (this seems to happen irregularly on this site) so apologies if this is off beam...

There are different types of stainless (ferritic, austenic & martensitic)

300 series are probably most common - these are austenitic, they work harden like crazy - but do not quench & temper

martensitic, can be quenched and tempered - think surgical blades

ferritic - I don't have much information to hand at present !

So some stainless grades can be quench hardened, but many can only be work hardened. You can sometimes (but not totally reliably) identify austentic steels as being non-magnetic (work hardening can tip them into being magnetic...).

Thread: Cool down a mini-mill motor.
14/01/2013 13:14:30
Posted by Michael Gilligan on 13/01/2013 15:04:45:


As a convenient point of reference [remembered from using laboratory glassware]

If you can just hold the palm of your hand on the motor, without pulling away ... it's probably around 70°C.


I'd suggest that the surface temperature probably isn't as high as that if you can hold your hand in place. Maybe with glassware you 'get away with it' because glass is not a fantastic conductor of heat, with metal object I certainly would not want to put my hand on anything very much above 50 C.

Thread: Which Stainless Steel?
02/01/2013 15:39:48

All 300 series (1.4404 equivalent to 316L ) will work harden. 400 series have different microstructure, less prone to work hardening, but not as widely available (and could be hardened by heat treatment anyway)

Use tapping drills on the larger side, and use a tapping compound.

Thread: Alibre 11.2
29/12/2012 21:33:01
Posted by Stub Mandrel on 29/12/2012 20:56:59:

Before jumping in, has anyone actually checked the Alibre T&Cs? ...


Yes - see my post earlier.

Alibre used to allow licence transfer/sale, but no longer do so.

29/12/2012 16:25:00
Posted by Siddley on 29/12/2012 16:12:37:

I might be stating the bleeding obvious here, but is the file format proprietary to Alibre ?
There are free viewers for most CAD files

3D files are an Alibre extension to STEP (which will import as STEP in some other CAD).

2D drawings derived from 3D are proprietary format (same as many other CAD systems).

There is a free viewer availble for Alibre as mentioned earlier (but this has to be provided via an existing user - you can't just browse to it on Alibre's web site).

29/12/2012 14:57:26

Have PM'd you a link.

29/12/2012 14:48:05

In addition to the free 30 day trial of Alibre (Professional), any current Alibre user can provide a link which will let you register for a free Alibre viewer - this is the standard Alibre software with content creation capabilities disabled.

A while back Alibre used to allow transfer of licence onward from the original buyer - the EULA was altered and now sellng/transferring the licence is not permitted.

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