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Hard Chrome

Posted by bill 
Hard Chrome
February 05, 2015 05:55PM
Does anybody have a good source for hard chroming piston rods? Thanks Bill
Re: Hard Chrome
February 06, 2015 03:05AM
Babbit Bearing in San Jose is good. Lot's of places can flash chrome, these guys can do that and/or overplate and grind to spec. in house.
Re: Hard Chrome
February 06, 2015 09:19AM
Bill for what type of engine.
For marine engines I always used Monel ground rod. It really got expansive.
I started using 440C ground stainless for 20 HP Stanley piston rods. But you can get ground hydraulic shafting in just about any size you want. My friend Dick had to replace the piston rods in his White and I told him to look at hydraulic shafting. He went to a place that rebuilds hydraulic cylinders and they gave him the rod as his needs were so small, worked out very well.

Re: Hard Chrome
February 08, 2015 12:15AM
Dear Bill Barnes, For about thirty years now, Art Hart and many others have been using the same California company to do all of our hard chroming on our piston rods. They grind them down to perfection, and then they hard chrome them and then regrind them back to the finished diameters. Nothing short of excellent work. Through the years I have had them do ten pairs for our cars and many more for my engine customers piston rods. Nowadays I do my best to not to take in anymore outside work. All five of our Stanleys have spare engines, and all of their piston rods are hard chromed too. Contact Electronic Chrome and Grinding Co. Inc. 912832 Dice Road, Santa Fe Springs, CA 90670 Phone (562) 946-6671 E Mail: bluecrowns@aol.com With hard chromes piston rods and the new Kevlar packing, At 40 mph, I can easily get up to 400 miles without touching my piston rod's stuffing boxes. The faster that I travel, the faster that the piston rod packing gets used up.
Re: Hard Chrome
February 10, 2015 04:46PM
Thanks I've been using John Crane 1625G Packing. Is Kevlar better?
Re: Hard Chrome
February 11, 2015 12:19AM
Bill, John Crane's 1625G is good packing and if needed, I would probably use it again because it is easier to work with than Kevlar packing. From McMaster Carr I bought a couple 25 foot spools of their sever service packing and only on the spools was listed the content of their packing as Kevlar being the predominate ingredient. It seems to wear longer that the 1625G. The only down side of it that I have noticed is that when it is pre-cut into the needed lengths for future use, it becomes unraveled rather quickly. So cut and use when needed. Pre-cut does not last. Find it at: [www.mcmaster.com] John Cranes' 1625 G is an over 1,000 degree packing where the McMaster Carr's sever service packing is rated at over 1200 degrees. With our five Stanleys, I keep a lot of packing to service all of their needs. Buying a couple of 25 foots rolls of Kevlar made more sense that buying the 1625G by the foot. In each steamer, I keep a small spool of different types of packing in its spare parts tray just in case. It seems that when I am out touring, some one is usually asking if I have any packing that I can spare them. Gas cars are usually the ones doing the asking.
Re: Hard Chrome
March 08, 2015 09:39AM
A bit off-topic, but I use piston rods from high quality pneumatic or hydraulic cylinders, preferrably Miller of Parker brands. These are very good finish, chromed, and far better than anything I can make with my shop equipment. They can be had in many lengths and diameters, and a little lathe work on one end will allow them to be used in almost any engine.

My steamboat (5/8 diameter piston rod, 5-1/2 inch stroke) has not had a rod packing changeout in 5 years now, have tightened the gland once or twice in those five years, with no leakage observed. I only use 100 PSIA steam, but many industrial/utility packings are rated for far greater pressure / temperature.
Re: Hard Chrome
March 08, 2015 12:43PM
One of the problems with chromed piston rods in higher temperature applications is that the coefficient of expansion of chrome is half that of steel and when piston rods go thru a great rise in temperature from room temperature the thin chrome plating is put under a good deal of tensile stress being stretched by the faster growing steel rod. I have known of a few Stanleys in the past that the chrome surface would reach that limit and the chrome surface broken and tear the hell out of the packing material. As far as packing materials for Stanleys my info is quite dated but talked to a senior packing engineer at Garlock and he still recommended Garlock 98 over the newer packings that were coming along for durability in Stanley piston rod packings. It was available at McMaster Carr back then and is quite expensive.
Re: Hard Chrome
March 08, 2015 03:54PM
For those that don't know, Garlock #98 is pure woven carbon filament packing, nothing else. Garlock also has pure woven graphite filament packing for even higher temperatures.

Quite right, hard chrome can flake off and tear the packing to shreds. In place of hard chroming engine piston rods, I have them centerless micro finished ground, ultra smooth.
The water pump plungers the same then hard chromed too for corrosion protection and long packing life. Rough rods and packing do not play well together.
I have used Garlock #98 since the beginning on the White and all the Dobles with total success.
Once it takes a set, you add one more ring and forget it. The cost has nothing to do with it, considering the time, money and effort spent on restoring one of these cars, the cost of the Garlick just doesn't matter.

Edited 4 time(s). Last edit at 03/08/2015 04:17PM by Jim Crank.
Re: Hard Chrome
March 08, 2015 06:51PM
A better choice than hard chrome is probably one of the thermal spray coatings. They can be applied in a few different methods using a variety of coating materials. Depending on the coating you can improve wear resistance, reduce or increase friction, reduce corrosion, retard thermal conductivity and so on. Ford is using thermal spray coatings directly into the aluminum bores of their new engines rather than using a centrifugally cast ferrous liner. Obviously the stuff is holding up to high temperatures if it will work on IC cylinder bores and piston crowns. I suspect it is more resistant to thermal expansion woes because it is penetrated into the base material rather than lying directly on the surface.


Re: Hard Chrome
March 08, 2015 07:56PM
There was a company in Kalamazoo Mich. that made nitrided piston rods. I checked them out back in 2005 or so when I was looking for resources.

What is the opinion on the possible use of nitrided rods?

Best Regards,

Bill G.
Re: Hard Chrome
March 09, 2015 10:45AM
Well, we nitride crankshafts and the bearing surfaces are definitely tougher and wear better.

Re: Hard Chrome
March 09, 2015 11:54AM
Just curious.
What is this fascination about thermal coating piston rods, why? I thought the requirement was that they be strong and very smooth so as not to tear the packing. Nitriding bearing surfaces does indeed make them really tough and hard. Interesting about Ford directly coating the cylinder bores in aluminum blocks, any steam engine applications here? Coating with what? Flame spraying, plating?
Once had a program at SRI to explosively clad aluminum cylinders for Porsche and Mercedes-Benz with a hard chrome alloy. Exploding aluminum wire under water with a big capacitor bank.

Edited 1 time(s). Last edit at 03/09/2015 11:57AM by Jim Crank.
Re: Hard Chrome
March 09, 2015 12:05PM
Some of these guys think we have all kinds of money. They should just try and buy a full role of packing some time, or just get some of these high end coating done.
The original packing in a Stanley engine was a fine braded copper wire graphite impregnated, I use a one ring of Garlock copper packing and one of graphite packing every other two rings, and you need to dig deep to pay for a full role.

Re: Hard Chrome
March 09, 2015 12:19PM
I just priced out a 1# roll of Garlock 98 1/4" size and it was somewhere around $250!!!! In the case of nitriding it takes special aluminum steels called Nitralloys and the process of building this superb hard surface takes 60-90 hours in a 1000F ammonia atmosphere. This is again possibly old archaic information of mine.. First of all I wonder what these special nitridable steels cost by themselves and what are there tensile strengths.
Cost for the hobbyist and that includes many Stanley owners and hobbyists put much of this stuff out of our budget.
Re: Hard Chrome
March 09, 2015 12:39PM
Nitride coating isn't very expensive, we wouldn't be putting it into automotive engines if it were. The nitride can be applied to various high end alloys but typically it is applied to low carbon, low alloy steels. Salt bath nitriding is basically a case hardening process. Gas nitriding involves heating the part and flowing ammonia over it, the ammonia breaks down and the nitrogen permeates the metal surface. And there is plasma nitriding wherein N2 (often combined with inert gases like argon) is permeated into the surface by creating plasmas through the use of strong electric fields. Titanium nitriding is more expensive as you are trying to penetrate titanium into the surface but even that has come down in cost over time.
Re: Hard Chrome
March 09, 2015 12:57PM
That may be relatively true for large quantities in the automotive industry where huge quantities of parts are done in a batch but for the hobbyist taking two Stanley piston rods and getting a two parts price from a local nitriding business is completely different. I would say your perspective from a General Motors viewpoint is quite different to the time and cost of an individual trying to get two piston rods done. And we still need to be concerned about the very high stresses on steam piston rods and the nitridable steels available costly for the hobbyist. As always I could be wrong.
Do you have any information or possible source of cost on a per two basis? Would love to know as I would not afford a 1# roll of Garlock 98 @ $250!! You are much more updated working at GM than I am on such matters.
Re: Hard Chrome
March 09, 2015 01:21PM
Hi George,

We get nitriding done by local vendors for single parts or small lots, I am in a prototype shop and not in an assembly plant. I'm sure we pay a premium over having parts done in mass production but to my knowledge the prices aren't that high.

To be clear, I am talking about Ferritic Nitrocarburizing, a process that many heat treat vendors provide. Despite the term carburizing in the title, it is a form of nitriding: Wikipedia

In my neck of the woods you can get a brief (and very incomplete) listing from the Tomcat website: vendors


Re: Hard Chrome
March 09, 2015 02:10PM
I have contacted a company called METLAB that does parts from a great range of weights and await their response. It will be interesting if they are interested in a few small parts and what the cost would be, surely shipping costs are a consideration. It appears that nitriding on 1020-1040 steels and 4130-4340 do not approach the hardness levels of Nitralloy steels, for the previous a Rc of 45-55 appears maximum from their tables..
Thanks for input, GeorgeN
Re: Hard Chrome
March 09, 2015 02:31PM
Just hear back from METLAB Company and the charge for small orders(like two Stanley piston rods) was $250 minimum plus 10%.
Possibly GM as a large and prestegious company could get them done for much less. My years long ago at MIT we could say we were doing prototype research and get such stuff done for free! Those good old days. Agree with Rolly on the high cost of things for the common steam hobbyist.
Ken maybe you could see how much you could get them done from GM for a different cost perspective?
Re: Hard Chrome
March 09, 2015 02:54PM
Hi George,

I opted not to do nitriding as I used a 17-4 PH h 1150rod. Nice tough stuff without having to heat treat. However, there was concern with corrosion resistance with the 17-4 as it has lower corrosion resistance nitrided so I did a multi-layer PVD. I don't think the steels are effected as much, but worth a check. I did check and it looks like 4130's corrosion resistance improves with nitiding.

Just a few hours of treatment should give .0004" of nitriding, close to hydraulic cylinder chrome thicknesses.

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File Name File Size   Posted by Date  
20 HP piston rod and crosshead guides.jpg 103.1 KB open | download Rolly 02/06/2015 Read message
P9140012.JPG 856.3 KB open | download Rolly 03/09/2015 Read message
vlave rods and packing.JPG 626.3 KB open | download Rolly 03/09/2015 Read message