Nylatron

Nylatron is a tradename for a family of nylon plastics, typically filled with molybdenum disulfide lubricant powder. It is used to cast plastic parts for machines, because of its mechanical properties and wear-resistance.

Bearings

From "Norman Gracy's Atlantic", Live Steam Magazine, December 1976:

John and Norm have been doing some experimenting with a new bearing material - molybdenum disulphide impregnated nylon (trade name Nylatron). It is available in round rod of various diameters. Norm and John have machined various journals and sleeves from it and found it almost unreal. For example: installed in the crosshead to main rod bearing, it showed no noticeable play or wear after six months whereas oilite bronze bushings have had to be replaced after six weeks of heavy running. This material requires no oil; in fact DO NOT oil.

GRWdriver wrote:

Paul Brien (Mid-South Live Steamers) installed Nylatron bearings and bushings on his first locomotive (7.5 inch gauge 0-6-0) in the late 1960s. Due to Paul's background as a tool & die maker, and later QC manager, he was inclined to make things to close fits. What he learned was that Nylatron has a relatively high coefficient of expansion and on it's first test steaming, as soon as his bearings and bushings heated up, the loco locked up solid. He discovered that anything made of Nylatron needed expansion clearance and once that was determined the Nylatron, and the loco which is still running, performed very well.

Bill Shields wrote:

I used Nylatron in the crosshead rod bearings of all my locos for 30+ years and have never had a problem. Do not BORE the holes...DRILL them and be sure that the stuff is COLD when you drill it.

Regarding contamination, Bill Shields wrote:

Properly applied, Delrin, Delrin AF, Nylatron, Rulon, etc, will all work.

The problem with any of these bearing types is how badly the can be torn up by contaminants...get a bunch of crap in there and they can dissapear in a hurry.

I have been using Nylatron (molydisulfide nylon) and Delrin AF bearings in my crossheads for decades - but they are in a location where I can fit them tight and not worry about dirt getting in - and their use in reciprocating load applications is far superior to bronze alloys.

Keep 'em clean and give them enough clearance so that they can grow properly under load, and there is no reason why these newer bearing materials shouldn't work very well.

Other Parts

Keith wrote:

I could not maintain grease between the spring loaded plungers (of my OS Mogul). No matter what I tried, any lateral movement of the pony truck wiped away the grease. I've made a new pair of plungers from Nylaton GS, they're the ones in the center with the springs. Heck, Nylatron works for pedestal liners on 6,000 HP diesels, why not here. The Nylatron was less that $8.00US from Online Metals.

OS Mogul pony truck spring loaded plungers made from Nylatron.

External Links

• "Nylatron", Wikipedia
• "Nylatron for bearings", Chaski.org