Grease zerk hole size??

G

Greenfrog

Member

• Mar 27, 2010

• #1

Without going into detail as to what for, I want to drill a hole, tap it, and put in a grease zerk. However, that seems to be pipe thread--I guess about 1/8 ((it always seem larger than what they call it..I have some quarter inch pipe and it is larger. Anyway, how do I tap threads..pipe threads--in that? SAE NF thread tap for bolts and nuts isn't right. Actually it is larger than 3/8 and smaller that 7/16. I don't really see any where on how to get that small of a pipe thread tap. This really should not be that difficult!!! I always thought that zerks were 3/8 fine thread. Thanks in advance for your input.

 

P

Pat-CT

Well-known Member

• Mar 27, 2010

• #1

I did alittle googleing, Im not sure if this would work for your solution but here ya go
poke here

 

T

Tramway Guy

Well-known Member

• Mar 27, 2010

• #1

1/8" NPT (National Pipe Thread). Should be available anywhere.....

 

O

old

Well-known Member

Location

Camdenton Missouri

• Mar 27, 2010

• #1

Zerks come in 3 or 4 different sizes if not more then that. As for pipe taps again you can get them at any good lumber or hardware store and also the bit you would need to drill the correct hole for them. Common tap and die sets almost always come with an 1/8 pipe tap by the way

 

K

ken in texas

Member

• Mar 27, 2010

• #1

it seemed that pipe size was concidered to be the inside of pipe, 1/8 being the inside, altho outside is much larger,therefore it iscalled a 1/8.Never figured why the did it that way.Zerks used pipe size so they would tighen going in the taper.

 

E

El Toro

Well-known Member

• Mar 27, 2010

• #1

They come in 1/4-28 threads too. In 90 or 45 degrees too. Hal

 

E

El Toro

Well-known Member

• Mar 27, 2010

• #1

Use a No3 tap drill for 1/4-28. Hal

 

J

Joe N E Texas

Member

• Mar 27, 2010

• #1

Yes the small ones will screw into a quarter inch fine thread nut . If you have something too thin to tap weld a nut on it and drill a small hole screw the zerk into the nut.

 

R

Rustyone

Member

• Mar 27, 2010

• #1

!/8-27 NPT tap and an 11/32 drill should do the job. Or a #3 drill for a 1/4-28 zerk

 

S

S2710

Well-known Member

• Mar 27, 2010

• #1

It has been many years but for 1/8 in. pipe I beleive you drill it 21/64 and tap it 1/8. If I am wrong someone will correct me.

 

A

Anonymous-0

Well-known Member

• Mar 27, 2010

• #1

A standard small set of tap and dies generally has a 1/8"-27 npt tap in it. If you are looking for taps, go to Enco or McMaster-Carr's web sites, they'll sell you a single tap, but its simpler to have the whole set, because the set generally comes with a card, which lists how big of a hole you need to drill, for each tap. Also, quality american taps, such as Hansen will have the drill size stamped or etched into the tap.

 

B

BarryfromIA

Well-known Member

• Mar 27, 2010

• #1

I agree with Rustyone. Also if you want be correct engineering wise there is a tapered counter sink to run in to the hole after drilling and before tapping. Generally only used in factory production.

 

G

gene bender

Well-known Member

• Mar 27, 2010

• #1

The hole depends on what size the zerk needs some are a press type fit and need no threads.

 

O

Oldmax

Member

• Mar 27, 2010

• #1

The small zerk is actually a 1/16" Pipe tap size. I had a 1/16" pipe tap that I got when I was working as a Mach Operator. However while on the last job it sprouted legs I have never been able to find another one the first one came in a set .

 

A

Anonymous-0

Well-known Member

• Mar 28, 2010

• #1

McMaster-Carr has 'em. But you have to need one to pay the price.

Gerald J.

 

A

Anonymous-0

Well-known Member

• Mar 28, 2010

• #1

Actually looking at McMaster-Carr, they have grease fittings in multiple threads. 1/8 (short and regular), 1/4, and 3/8 (short and regular) pipe thread, 1/4-28 taper or 1/4-28 straight UNF. 5/16"-24 UNF, 3/8-24 UNF, and 5/16-32 UNEF. Plus there's 1/8 and 1/4 British standard pipe thread and M6, 8, 10, 12, and 14 mm. with two thread pitches in 8, 10, and 12 mm.

I'm sure the local farm and hardware stores have only pipe threaded 1/8, and 1/4-28, none of the others.

Gerald J.

 

E

El Toro

Well-known Member

• Mar 28, 2010

• #1

Use a Q or R drill for 1/8 pipe threads, 7/16 drill for 1/4" pipe. Hal
PS: I used 1/4-28 zerks on this tiller where it slides up and down on on those pins when engaging or disengaging the drive wheels.

 

N

Nebraska Cowman

Well-known Member

• Mar 28, 2010

• #1

1/8 pipe is the size of your grease gun pipe. Yeah, it's about quarter ince to look at it. 3/8 and quarter inch pipe are bigger yet. The smaller grease zerks are bolt thread.

 

B

Bspauld

Member

• Mar 28, 2010

• #1

I have done that many times works great on thin wall material. but now some fittings are metric

 

L

larryd

Member

• Mar 28, 2010

• #1

autmotive grease zerk is 1/4 28 NF thread same as a 1/4 NF bolt ,this is not pipe thread. you can have 1/4 ,3/8 ,1/2 pipe thread grease zirks used on industrial equipment.You can have a 1/4 28 NF Bolt thread & A 1/4 in pipe thread they are not the same.

 

OP

OP

G

Greenfrog

Member

• Mar 30, 2010

• #1

Thanks all you guys for a good discussion on this zerk topic. This all helped. Greenfrog