Grease & Zerk Fittings

What are Grease Lubrication Fittings?

Grease fittings, also known as Zerk fittings, are metal fittings for mechanical systems so that they can feed lubricants into various bearings using a grease gun with medium to high pressure. Aetna offers a complete line of Zinc Plated zerk fittings with various grease lubrication fitting sizes that are designed for heavy industrial applications. They are used by industries, such as material handling, automotive, heavy truck, conveyer & mining.

Aetna's grease fittings are made of case hardened steel and are heavily zinc plated for maximum corrosion resistance and are manufactured to exacting specifications.

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Zerk Fitting Standards

Our Zinc Plated Zerk Fittings meet or exceed all commercial standards, and conform with the following:

SAE Specification J-5343
Military Specification F-3541

Grease Fitting Sizes

AETNA PART NO.	Description	A	B	C	D	E	F	G	H	INTERCHANGEABLE PART NUMBERS
AETNA PART NO.	Description	A	B	C	D	E	F	G	H	Alemite	GM	American Lube	LINCOLN
5540000	1/8" PTF Airvent	25/32	17/64	13/16	.400	1/8 PTF	7/16	-	Str.	301370	271420		5698
5546006	1/8" PTF-SS	11/16	9/32	3/16	13/32	1/8 PT	7/16	-	Str.	1610-BL	9411010	T-7000	5000
5546010	1/8" PTF-SS	1-1/4	3/4	-	.400	1/8 PT	7/16	-	Str.	1607-BG	271281 / 9411011	T-7003	5003
5546017	1/8" PTF-SS	7/8	19/64	7/32	13/32	1/8 PT	7/16	27/64	45¡	1688-B	271283 / 9411016	T-7008	5200
5546018	1/8" PTF-SS	27/32	19/64	7/32	13/32	1/8 PT	7/16	1/2	65¡	1612-B	271284 / 9411017	T-7010	5300
5546026	1/8" PTF-SS	27/32	19/64	7/32	13/32	1/8 PT	7/16	33/64	90¡	1613-B	271285 / 9411019	T-7013	5400
5546052	1/8" PSTDT	5/8	15/64	-	.400	1/8 PTF	7/16	-	Str.	1720-B	273321 / 9411025		205000
5546056	1/8" PSTDT	49/64	13/64	-	.400	1/8 PTF	7/16	17/32	90¡	1723-B	273324 / 9411025	T-7302	205400
5546030	1/4"-28 TT-SEA-LT	35/64	13/64	7/64	1/4	1/2-28	5/16	-	Str.	1641-B	271287 / 9411027	T-7201	5010
5546032	1/4"-28 TT-SEA-LT	11/16	23/64	13/64	1/4	1/4-28	5/16	-	Str.	1652-B	273326 / 9411028	T-7202	5013
5546034	1/4"-28 TT-SEA-LT	31/32	5/8	13/64	.260	1/4-28	5/16	-	Str.	1680-B	271228 / 9411029	T-7203	5014
5546044	1/4"-28 TT-SEA-LT	49/64	13/64	5/32	1/4	1/4-28	3/8	1/2	90¡	1911-B	274510 / 9411032	T-7208	5410
5546064	3/16" Drive Type	33/64	15/64	-	3/16	-	5/16	-	Str.	1728-B	-	T-7605	5033
5546084	1/4" Drive Type	15/16	19/64	-	.260	1/4-28	3/8	25/64	45¡	1744-BI	-	T-7614	5318
5546000	5/16" Drive Type	21/64	9/32	-	-	-	-	-	Str.	1814	-
5546106	1/4-28 UNF-2A	31/64	9/64	-	.250	1/4-28	9/32	-	Str.	1792-B	271291 / 9411244		5527
5546029	6 x 1 Metric	35/64	3/16	5/32	15/64	M6X1	7mm	-	Str.	2106	-	T-7402	5175

For more information, please scroll to the right.

Symbols	Definitions
PTF	Dry seal American Standard Taper Pipe Thread, where full thread length has been shortened by one thread on small end.
PTF-SS	Same as PTF except on full thread has been shortened from large end of thread.
PSTDT	1/8" Pipe Special Taper Drive Thread - Thread forming forms thread in mating part during installation - when removed can be replaced by standard 1/8" PTF series fitting.
TT-SEA-LT	1/4" Taper Thread (SEA-LT) - Thread has a 3/4" taper per foot and a pitch diameter of .2257/.2224 at small end. The mating tapped hole is 1/4"-28 UNF-3B straight thread. Tap drill must not exceed .215" diameter.

Lincoln Grease Fittings

AETNA/LINCOLN FITTING NUMBER	National Stock Number (NSN)	Military Standard Number
5010	4730-00-050-4203	MS15001-1
5014	4730-00-172-0001	MS15001-2
5410	4730-00-050-4207	MS15001-4
5000	4730-00-050-4208	MS15003-1
5003	4730-00-172-0022	MS15003-2
5200	4730-00-172-0028	MS15003-4
5300	4730-00-172-0031	MS15003-5
5400	4730-00-172-0034	MS15003-6

Grease Fitting Thread Size

grease fitting thread size

Nominal Pipe Thread Size	Threads Per Inch	Major Dia. B or C	Nominal Engagement for Tight Joint A
1/8"	27	.405"	1/4"
1/4"	18	.540"	3/8"
3/8"	18	.675"	3/8"
1/2"	14	.840"	1/2"
3/4"	14	1.050"	9/16"
1"	11/1/02	1.315"	11/16"

Fitting Thread Size	Tap Drill Selection For Standard Thread Fittings	Drill Size Selection for Spin Drive Fittings
1/4"-28	#3 (for soft metal use #5)	"A" - .234" Dia.
5/16"-32	9/32" (for soft metal use "J")	-
1/8" Pipe	11/32" (for soft metal use "R")	3/8 - .375" Dia.*
1/4" Pipe	7/16"	-

When selecting a lubrication fitting (straight, angle, standard thread, spin drive or straight drive) be sure to measure engagement depth "A", taking manufacturing tolerance into consideration. Then select fitting with thread length or drive shank length that will not penetrate bearing material or rest against rotating member.

The turning radius is given for all angle fittings shown on these pages. Take this into consideration during initial machine design, and select a fitting with a turning radius that will permit easy production line installation.

When deep set fittings are required, make sure there is sufficient clearance for easy disengagement of hydraulic coupler.

Lincoln hydraulic couplers and fittings are designed to provide angle up to 15°.Movement beyond this angle will cause coupler to disengage.

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