linear bearing bar

I am trying to find a supplier of 1" diameter hardened and chrome plated bar for use with linear bearings. I can find 25mm bar and 1" carbon steel bar but I really need 1" chrome plated. I seem to recall an ebay supplier ( not Marchant-Dice ) selling this some time ago but I didn't take a note of the supplier at the time and can't find anything on ebay now. Any help would be appreciated.

Doug

http://www.thomsonlinear.com/website/com/eng/products/linear_guides/shafting/standard_shaft.php

not cheap but very good. Used their chromed shafting many times in industry with success. JD

Hello Douglas,

Try hydraulic ram workshops, they sell what you need and will cut to length but I am not sure if they still stock imperial sizes. I made a full length taper turning guide using ram material, it is as straight as a die and thickly hard chromed.

Linear bearings can be found by googlling linear bearing suppliers.

Regards

Brian

Thanks for the replies, ram workshops are probably a good idea since big corporations like Thomson won't deal with a guy looking for a metre of bar. I have not been able to track down a local ram workshop in the east coast of Scotland but I will continue looking.

Doug

FleeBay have adds for linear bearings and rails.

Paul

Hi Douglas

Hydraulic shops may not be the answer? If you are intending to run linear ball bearings on the shaft it needs to be heavily case hardened to around 55 to 60 Rockwell. A long time ago I tried to use softer material on a small project thinking that with a lighter load it would be OK. That was a bad assumption, the balls quickly indented the material.

One source that does get mentioned around the traps is Linearmotionbearings2008 **LINK** I have no connection with the company apart from being a potential customer. I have been communicating by email lately about a quote for a set of profile rail linear bearings and ball screws. His responses have been prompt and courteous and the prices quite good. Now all I need to do is to finalise the design.

Regards
John

That is an interesting observation John, I had thought hydraulic ram rods were a similar spec to linear bearing rails but that may not be the case. I suppose hydraulic rams don't need to be that hard under the chrome plating as there won't be much load on the surface of the rod..

The 1" chrome plated rails I am looking for seem to be much easier to get in America, things seem to be more metric here in the UK.

Doug

Hardened linear bar for use on linear bearings

is not chrome plated.

All ours comes from ina uk. Brian

Edited By Boiler Bri on 29/05/2015 14:35:51

I agree, chrome will peel of if it picks up muck, it is hardened bar that you require.

Martin P

Zapp Automation?

The only reason I wanted chrome plated bar was to reduce the chance of corrosion, but perhaps I should heed the warnings and go for the hardened carbon steel which I can get hold of in 1" size from Marchant-Dice. It is cheaper anyway than the chrome plated stuff. Thanks for all the input.

Doug

You can get hardened and ground stainless steel linear bar.

Bri

Try HTS on 01484 533356 (satisfied customer) 

Edited By Boiler Bri on 29/05/2015 21:43:52

"Show" chrome might, (copper/nickel/chrome). Chromium is a hard colourless coating. Perhaps someone involved in the Hard chrome plating industry could elucidate.

Regards Ian.

Ian,

After forty years as a machine tool fitter on all manner of machine tools I've seen it happen, even hardened bar will show signs of wear from the the balls running up and down the bar if not lubricated regularly.

Martin P

I think there might be a bit of confusion here:

Hard chrome plating is a substantial coating of chrome metal which is very hard. Thus it has good wear resistance. Chrome metal is a silvery grey lustrous element similar in appearance to many other metals.

In stainless steels, the chromium content forms a thin, self passivating oxide coating which protects the iron from oxidation and hence further corrosion. This thin oxide layer is transparent.

HTH

Rod

A good way to test for hard chrome plating is to try a hacksaw on an area which does not show. If it is proper hard chrome - put on thick and ground to size - it won't show any sign of the saw. Decorative chrome, even high quality stuff, will risk peeling if used as a bearing surface. The visual effect is much the same, the bluish colour does not help to distinguish. The price is a good guide, though, as hard-chrome is ever-so expensive.

Cheers, Tim