small grease zerk thread size

[Wilson]

Need to tap out threads for small zerk. It's much smaller than one eight pipe. What tap size do I use????

 

[Duner Wi]

Probably 1/4" by 28 TPI. Try zerk in a nut first.

 

[Wilson]

good idea thanks

 

[JML755]

Depending upon what the zerk is for, it may be metric. Just ran into that 2 wks ago. Was frustrated because Tractor Supply and the several auto parts chains I stopped at only sold the kits with a variety of zerks. I needed a 45 deg what I thought to be 5/16x24 (had used that size tap & die on the zerk and it's hole to measure). Stopped in at a NAPA store and the guy was scratching his head, saying THAT's an odd size. When I mentioned Italian, light bulb went on for both of us: METRIC. Turned out to be M8x1.0.

 

[Oldmax]

It is a 1/16 Pipe tape. and they are like hens teeth. The guy that worked with me lifted "Stole" the last one I had about 8 years ago and I havent been able to find one since.

 

[oldhousehugger]

Because the 1/4-28 NFT tap is a straight not a tapered thread I use just the first several turns of the tap. That way the tapered zerk thread has something to wedge up agianst. Otherwise the zerk will never tighten up.
I worked in a machine shop where we installed a lot of zerks and never used anything but standard 1/4-28 taps on the zerks. They are common and cheap.
John

 

[Dell (WA)]

Wilson........define small.....could be 10-32 ........ NOT all zerks are pipe thread ........Dell

 

[oldts]

Most grease fittings on machinery are 1/8 npt, but if you are needing a smaller one, or and can"t find one that fit"s it will usually be a 1/4 28, this is referred to as an automotive grease fitting. These are used on most u-joints, tie rod ends, and ball joints. Most NAPA stores stock them.

 

[bob featherstone]

usually 10-32
bob

 

[greygoat]

A Machine shop supply outlet should have a 1/16
inch pipe tap. I got mine from VICTOR tool
supply. Hobbyists who make model engines and
steam engines use such things

 

[rodm1]

(reply to post at 18:00:35 10/15/10) It is a 1/16 Pipe tape. and they are like hens teeth. The guy that worked with me lifted "Stole" the last one I had about 8 years ago and I havent been able to find one since.

http://www.use-enco.com/CGI/INSRIT?PMAKA=313-4006&PMPXNO=2670702&PARTPG=INLMK32