Thread: Silver Steel

I have seen the guys at TAFE doing similar things. They normally turn it to within .002 then they harden it by heating in the oven and quenching, then , to remove any distortion , they finish it on the cylindrical grinder to its final dimension. MIKE.........BTW there is a place just off Greens road in Dandenong that sells hardened ground shafting in various sizes . They even have some imperial stuff ... I bought some 3/4" lengths , but it's extremely difficult to turn in a lathe , took me an hour to remove about 1/4" . They mostly have metric sizes . They also sell those trapezoid screws and nuts for CNC machines.... They sell to the public as well .... Can't think of the name right now , it's on a side street off Greens road, just up from Action Aluminium.Last time I was there, the counter guy gave me a free length of 22 mm ground bar , he mentioned he has a Hercus lathe at home .

thanks for reply. Do I HAVE to harden the silver steel if it is going to run in cast iron bearing? I have finished shaft to about plus/minus .05mm along length - not exactly sure but fit is good "feel" in cast iron bearing. It would not take much distortion to alter this nice fit so am reluctant to heat to cherry red for hardening and then to straw-ish for tempering.

4140 grade steel might be better for your application. Others will know more, but untreated silver steel or drill rod would be too soft I would think . Mike

The originals were not hard.

this might help

Originally Posted by YarrD

Dear All

I have turned a new silver steel counter shaft for my lathe (hercus) as part of a project to make a clutch for the lathe along the lines of the clutches on Myfords. I have turned the shaft to final dimensions and am very pleased with how close I got it to 19mm all the way along so it runs nicely in the cast iron bearings on the hercus countershaft. I have also bored it down the centre to take a pushrod. BUT, I suppose I should harden and temper it...what risks that this process buggers up my nice, straight, fairly accurate 19mm counter shaft?

David

I would be inclined to leave it as is.
Providing you have a fine finish on the shaft (Ideally polished) then it will probably outlast you, providing the lubrication is kept up to it in operation.
Agree with Pipeclay the originals were left soft & they lasted a long time.
You could get distortion in heat treating.
regards
Bruce

David

Have you seen this Hercus 9" Lathe Countershaft Bearings

good advice from peoples thanks (ie advice that I really wanted to hear) - I tested my current countershaft with hacksaw and is unhardened. I really do have nice fit in bearing and would not want to lose it (I struggle to get nice fits). I will polish the silver steel and leave it as is. BTW, silver steel is wonderful..it turned nicely and drilled nicely...magic

Originally Posted by YarrD

good advice from peoples thanks (ie advice that I really wanted to hear) - I tested my current countershaft with hacksaw and is unhardened. I really do have nice fit in bearing and would not want to lose it (I struggle to get nice fits). I will polish the silver steel and leave it as is. BTW, silver steel is wonderful..it turned nicely and drilled nicely...magic

Well done YarrD !
Yes I have found Silver Steel to be nice to machine ,drill, & tap,etc Plus its good to start with a nice piece of ground material for setting up with dial gauges.
Good for self centering chucks, & collet holding.
I am sure you will be happy with this as a countershaft for the lathe.
Bruce