Are all zerks/grease fittings the same?

PA hayseed · Jul 23, 2018

I am not talking about sizes of threads or straight versus angled, I am talking about manufacturers. I was just thinking about this and thought I would ask those who know. I can only assume it is like anything else, quality parts or inferior parts.

It seemed like a trivial item to me until I noticed I have to replace two zerks on my woods RFM again. It is a 7footer and it gets used quite a bit. They must spin loose or something, or the lawn fairy took them. I noticed at most recent greasing of myself and my equipment. I know I could carefully apply some thread lock on it, but I never do. My lock and lube helps keep me mostly grease free nowadays, but you know how it is, clean the dirt and grease from a couple of areas before applying new grease and walla! you look down and have grease on you.

Now if I could just find the dam pins that came off ... that is another issue.

FWIW, those that need all the background info, I cut 9 acres around my house like most people cut their 1/3 acre lawns (yes I am weird - but it gives me a clean line of sight to the critters and keeps ticks and snakes down to nothing). I use the 7' RFM and a Woods ZTR. On lucky days I get some assistance from SWMBO or the kid. When the sun shines on my butt and I win the lottery they both come out to help and it gets done fast with three pieces of equipment working. Once in 11 years, but that is another story....

Industrial Toys · Jul 23, 2018

Can a north american zerk be the same nipple size as one from afar?

Many have precious little thread to keep them in, and tapered at that. A quarter turn and they are ready to fall out.

IchabodCrayne · Jul 23, 2018

They are supposed to be "industry standard" but like all things made here or there (China) tolerances are different. Pick a handful and some are tighter than others. Many replacement lawn mower spindles with zerks in them actually have no threads cut in the holes. Zerks are just forced in and held by friction of crushed threads.

Industrial Toys · Jul 23, 2018

I'm actually guessing, they are more a type of self tapping thread.

Sawyer Rob · Jul 23, 2018

There ARE different thread sizes, then some are NOT threaded at all, just pounded in.

SR

PILOON · Jul 23, 2018

Sawyer Rob said:
There ARE different thread sizes, then some are NOT threaded at all, just pounded in.

SR

Yep, some are pipe thread, some straight thread and then SAE or metric.
Then U have 1/8 NPT and 1/4. and as said some simply pressed in.

Then I have an oddball that is like a mushroom head that takes a special gun head. (not on anything I own but just lose in my tool box)

Captain Dirty · Jul 23, 2018

PILOON said:
Yep, some are pipe thread, some straight thread and then SAE or metric.
Then U have 1/8 NPT and 1/4. and as said some simply pressed in.

Then I have an oddball that is like a mushroom head that takes a special gun head. (not on anything I own but just lose in my tool box)

The head of a grease gun is somewhat similar to a drill chuck; there is a slight amount of adjustability that may adapt to manufacturing tolerances. (Turning the end of the tip counterclockwise when viewed as the greaser tightens. It is possible to be too tight to install or remove without loosening) The zerk head can also wear; my JD front mower has zerks on the spindles below the deck where they are subject to the erosive dust and dirt on my "lawns". Also the zerk heads can be physically damaged so the gun will "fit" but pumps grease out the sides; the zerk has to be replaced.
If the zerk has wrench flats (like a hex nut) it probably is threaded. If there are no flats it probably was pressed in. Take the old zerk and a magnifier when you go to buy replacements. As mentioned there are a myriad of threads; these old eyes have trouble differentiating 1/4-28 from 6mm-1.0mm (0.24" x 25 tpi). In my experience, the fact that other fasteners on the implement are SAE or metric has no correlation to the zerk.