ASME B16.9 Stub End Archives | Quality Manufacturer of Industrial Pipe Fittings

ASME B16.9 Stub End Dimensions

zhao77jie — Tue, 06 Jan 2026 01:55:50 +0000

In the field of pipeline engineering, the ASME B16.9 standard serves as the core specification for pipe fitting manufacturing, providing a unified basis for the dimensions, materials, and performance of various butt weld fittings. Among them, the ASME B16.9 Stub End dimensions, valued for its convenience and reliability in pipeline connections, is widely used in industries such as petroleum, chemical, and power generation.

ASME B16.9 defines the technical requirements for butt weld pipe fittings made from carbon steel, alloy steel, and stainless steel, covering dimensions, tolerances, marking, testing, and material properties. In particular, the dimensional accuracy of Lap Joint Stub Ends—including carbon steel stub ends and stainless steel stub ends—directly affects the sealing integrity, pressure-bearing capacity, and overall adaptability of the piping system. Therefore, these parameters are closely monitored by engineers, procurement teams, and construction personnel alike.

In addition to ASME B16.9, the MSS SP-43 standard also applies to Stub Ends and other wrought stainless steel butt weld fittings, particularly for lightweight and corrosion-resistant applications. While ASME B16.9 primarily covers fittings designed for higher pressure and heavier wall thicknesses, MSS SP-43 specifies dimensions for fittings with schedule 5S, 10S, and 40S wall thicknesses, commonly used in low-pressure or non-critical stainless steel piping systems.

By understanding the relationship between ASME B16.9 and MSS SP-43, industry professionals can accurately select the proper Stub End type based on pressure rating, material grade, and installation requirements—ensuring both performance and cost-effectiveness in pipeline design and construction.

Butt Weld Stub End Specification

ASME B16.9 Standard

This Standard covers overall dimensions, tolerances, ratings, testing, and markings for wrought factory-made buttwelding fittings in sizes NPS 1;2 through 48 (DN 15 through 1200).

Generally speaking, the maximum size of a stub end is 24 inches. This is because it is often used with a lap joint flange. According to the ASME B16.5 standard, the maximum size range of a lap joint flange is only 24 inches. Therefore, the size of the stub end is also limited to this range.

A Stub End is a common butt weld pipe fitting typically used with Lap Joint Flanges. One end is designed for butt welding to steel pipes, while the other features a flanged structure for mating with lap joint flanges.

Stub Ends are categorized into Short Pattern and Long Pattern based on length, with dimensions specified by the ASME B16.9 standard.

Long Pattern Stub End Dimensions

Nominal Size		OD of Cylinder		Length	Radius of Fillet		Diameter of Lap
DN	NPS	OD		F	R		Diameter of Lap
DN	NPS	Max.	Min.	Long Type	A	B max	G
15	1/2	22.8	20.5	76	3	0.8	35
20	3/4	28.1	25.9	76	3	0.8	43
25	1	35.0	32.6	102	3	0.8	51
32	1 1/4	43.6	41.4	102	5	0.8	64
40	1 1/2	49.9	47.5	102	6	0.8	73
50	2	62.4	59.5	152	8	0.8	92
65	2 1/2	75.3	72.2	152	8	0.8	105
80	3	91.3	88.1	152	10	0.8	127
90	3 1/2	104.0	100.8	152	10	0.8	140
100	4	116.7	113.5	152	11	0.8	157
125	5	144.3	140.5	203	11	1.6	186
150	6	171.3	167.5	203	13	1.6	216
200	8	222.1	218.3	203	13	1.6	270
250	10	277.2	272.3	254	13	1.6	324
300	12	328.0	323.1	254	13	1.6	381
350	14	359.9	354.8	305	13	1.6	413
400	16	411.0	405.6	305	13	1.6	470
450	18	462.0	456.0	305	13	1.6	533
500	20	514.0	507.0	305	13	1.6	584
550	22	565.0	558.0	305	13	1.6	641
600	24	616.0	609.0	305	13	1.6	692

Short Pattern Stub End Dimensions

Nominal Size		OD of Cylinder		Length	Radius of Fillet		Diameter of Lap
DN	NPS	OD		F	R		Diameter of Lap
DN	NPS	Max.	Min.	Short Type	A	B max	G
15	1/2	22.8	20.5	51	3	0.8	35
20	3/4	28.1	25.9	51	3	0.8	43
25	1	35.0	32.6	51	3	0.8	51
32	1 1/4	43.6	41.4	51	5	0.8	64
40	1 1/2	49.9	47.5	51	6	0.8	73
50	2	62.4	59.5	64	8	0.8	92
65	2 1/2	75.3	72.2	64	8	0.8	105
80	3	91.3	88.1	64	10	0.8	127
90	3 1/2	104.0	100.8	76	10	0.8	140
100	4	116.7	113.5	76	11	0.8	157
125	5	144.3	140.5	76	11	1.6	186
150	6	171.3	167.5	89	13	1.6	216
200	8	222.1	218.3	102	13	1.6	270
250	10	277.2	272.3	127	13	1.6	324
300	12	328.0	323.1	152	13	1.6	381
350	14	359.9	354.8	152	13	1.6	413
400	16	411.0	405.6	152	13	1.6	470
450	18	462.0	456.0	152	13	1.6	533
500	20	514.0	507.0	152	13	1.6	584
550	22	565.0	558.0	152	13	1.6	641
600	24	616.0	609.0	152	13	1.6	692

Stainless Steel Lap Joint Stub End Tolerance as per ASME B16.9

DN	NPS	OD	ID	H F	G	R	t
15-65	1/2 -21/2	+1.6 -0.8	± 0.8	± 2	0 -1	0 -1	+1.6 0
80-90	3-31/2	± 1.6	± 1.6	± 2	0 -1	0 -1	+1.6 0
100	4	± 1.6	± 1.6	± 2	0 -1	0 -2	+1.6 0
125-200	5-8	+2.4 -1.6	± 1.6	± 2	0 -1	0 -2	+1.6 0
250-450	10-18	+4.0 -3.2	± 3.2	± 2	0 -2	0 -2	+3.2 0
500-600	20-24	+6.4 -4.8	± 4.8	± 2	0 -2	0 -2	+3.2 0

MSS SP-43 Standard

MSS SP-43 standard lap joint stub ends are available in sizes ranging from NPS ½ to NPS 24. Manufactured from stainless steel, MSS SP-43 stub ends are suitable for use with Schedule 5S and Schedule 10S pipes, while stub ends are compatible with Schedule 40S pipes. MSS Type A stub ends conform to industry specifications for use with standard flat lap flanges.

MSS SP-43 Stub End Dimensions

Dimensions of Lap-Joint Stub Ends and Caps
Dimensions are in inches.
NPS	Nominal O. D. at Bevel	Length F	Diameter of Lap G (Nominal & Max.)	Radius of Fillet
NPS	Nominal O. D. at Bevel	Length F	Diameter of Lap G (Nominal & Max.)	A Nominal&Max	B (Max.)
1/2	0.84	2.00	1.38	0.12	0.03
3/4	1.05	2.00	1.69	0.12	0.03
1	1.32	2.00	2.00	0.12	0.03
1 1/4	1.66	2.00	2.50	0.19	0.03
1 1/2	1.90	2.00	2.88	0.25	0.03
2	2.38	2.50	3.62	0.31	0.03
2 1/2	2.88	2.50	4.12	0.31	0.03
3	3.50	2.50	5.00	0.38	0.03
3 1/2	4.00	3.00	5.50	0.38	0.03
4	4.50	3.00	6.19	0.44	0.03
5	5.56	3.00	7.31	0.44	0.06
6	6.62	3.50	8.50	0.50	0.06
8	8.62	4.00	10.62	0.50	0.06
10	10.75	5.00	12.75	0.50	0.06
12	12.75	6.00	15.00	0.50	0.06
14	14.00	6.00	16.25	0.50	0.06
16	16.00	6.00	18.50	0.50	0.06
18	18.00	6.00	21.00	0.50	0.06
20	20.00	6.00	23.00	0.50	0.06
24	24.00	6.00	27.25	0.50	0.06
NOTES: (a) Minimum lap thickness shall not be less than nominal wall thickness. (b) Connect faces of stub ends shall have a modified spiral or concentric serration. (c) These lengths and radii for use with Schedule 40S or thinner pipe.

Lap Joint Stub End Weights

Nominal Size		Sch10S		Sch40S		Sch80S
DN	NPS	Long Pattern	Short Pattern	Short Pattern	Long Pattern	Short Pattern	Long Pattern
15 20 25	1/2 3/4 1	0.07 0.09 0.15	0.09 0.12 0.25	0.09 0.12 0.18	0.12 0.16 0.32	0.12 0.15 0.24	0.16 0.21 0.43
32 40 50	11/4 11/2 2	0.19 0.22 0.35	0.34 0.39 0.71	0.25 0.31 0.52	0.43 0.52 1.02	0.33 0.43 0.73	0.57 0.75 1.49
65 80 90	21/2 3 31/2	0.46 0.62 0.70	0.95 1.22 1.36	0.81 1.10 1.52	1.60 2.11 2.55	1.10 1.50 2.09	2.22 2.98 3.65
100 125 150	4 5 6	0.94 1.30 1.75	1.59 2.80 3.30	1.80 2.25 3.59	3.05 5.42 7.02	2.58 3.60 5.76	4.44 7.86 11.3
200 250 300	8 10 12	2.90 4.79 7.20	4.95 8.50 10.9	5.98 10.2 14.9	10.6 18.4 22.8	9.18 13.7 19.5	16.2 24.9 30.2
350 400 450	14 16 18	7.95 9.50 11.1	15.0 17.3 19.8	15.8 18.9 22.0	28.7 33.1 38.0	21.6 25.2 29.3	38.6 44.5 51.1
500 550 600	20 22 24	14.1 16.5 19.8	25.9 28.2 35.0	24.3 – 29.6	42.3 – 51.2	32.6 – 39.7	56.8 – 68.8

Stub End Material

Stainless Steel Buttweld Long Stub End :
ASTM A403 WP316/316L, ASTM A403 SA / A 774 WP-S, WP-W, WP-WX 304/304L, ASTM A182 F316L, 304L, DIN 1.4301, DIN1.4306, DIN 1.4401, DIN 1.4404

Duplex & Super Duplex Steel Buttweld Long Stub End :
ASTM A 815, ASME SA 815 UNS NO S31803, S32205. UNS S32750, S32950. Werkstoff No. 1.4462

Carbon Steel Buttweld Long Stub End :
ASTM A234, ASME SA234 WPB , WPBW, WPHY 42, WPHY 46, WPHY 52, WPH 60, WPHY 65 & WPHY 70.

Low Temperature Carbon Steel Buttweld Long Stub End :

ASTM A420 WPL3/WPL6

Alloy Steel Buttweld Long Stub End :
ASTM / ASME A/SA 234 Gr. WP 1, WP 5, WP 9, WP 11, WP 12, WP 22, WP 91

Nickel Alloy Buttweld Long Stub End :
ASTM B336, ASME SB336, Nickel 200 (UNS No. No2200), Nickel 201 (UNS No. N02201), Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500), Inconel 800 (UNS No. N08800), Inconel 825 (UNS No. N08825), Inconel 600 (UNS No. N06600), Inconel 625 (UNS No. N06625), Inconel 601 (UNS No. N06601), Hastelloy C 276 (UNS No. N10276), Alloy 20 (UNS No. N08020), Titanium (Grade I & II), Cupro-Nickel 70/30, CuNi10Fe1Mn, CuNi30Mn1Fe.

The post ASME B16.9 Stub End Dimensions appeared first on Quality Manufacturer of Industrial Pipe Fittings.

Application of Stainless Steel Stub End

zhao77jie — Wed, 10 Jul 2024 08:38:39 +0000

Stainless steel stub end is a type of butt welded pipe fittings. It usually used in conjunction with lap joint flange to achieve flange connection in pipeline systems. The stub end section is generally formed by stamping technology. It’s divided into long and short stub end according to the length of the straight pipe end. The selection of forming methods confirms that the product is not damaged. Some large diameter flanges still require welding technology. The production standards for stub end mainly comply with the American production standards ANSI/ASME B16.9 and MSS SP-43.

ASME B16.9 stainless steel stub end can be divided into long and short stub ends based on their length.

Type	Long Pattern (LP) and Short Pattern (SP)
Size Range	1/2” – 24” / DN15 – 600
Thickness Schedule	SCH10S/SCH40S/SCH80S
China Standard	GB/T12459, GB/T13401, HG/T21635/21631, SH3408/3409
America Standard	ANSI / ASME B16.9 / MSS SP 43
Japan Standard	JIS B2311/2312/2313
Germany Standard	DIN2605/2615/2616/2617
Europe Standard	EN10253
Stainless Steel	ASTM A403 WP304/304L/304H, 316/316L, 310S, 317,347,904L
Duplex Stainless Steel	ASTM A815 S32205, S31803, 32750, 32760

Material Standard for Stainless Steel Stub End

Stainless steel stub ends are produced using high-quality stainless steel materials. Stainless steel mainly have characteristics such as corrosion resistance, high temperature resistance, and stable performance. They are suitable for various types of pipeline systems and application environments. The common stainless steel material standard is the American standard ASTM A403. This standard includes different grades of stainless steel, such as ASTM A403 WP304/316, etc.

Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Ni	Cr	Mo
ASTM A403 WP304	MIN						8.0	18.0
ASTM A403 WP304	MAX	0.08	2.00	0.045	0.030	1.00	11.0	20.0
ASTM A403 WP316	MIN						10.0	16.0	2.00
ASTM A403 WP316	MAX	0.08	2.00	0.045	0.030	1.00	14.0	18.0	3.00

Mechanical Properties

MATERIAL	ASTM A403 WP304	ASTM A403 WP316
T.S (MPA)	515 min	515 min
Y.S (MPA)	205 min	205 min
EL %	28 min	28 min

ASME B16.9 Specification

ASME B16.9 is one of the main manufacturing standards for stainless steel stub end. This standard specifies key parameters such as dimensions, tolerances, material requirements, and inspection methods for stub end. In specifications, the size range of stub end is from 1/2 “to 24”. It can meet the connection requirements of pipes with different diameters.

Dimension of ASME B16.9 Stainless Steel Stub End

DN	NPS	OD		F		R		G
DN	NPS	Max.	Min.	Long Type	Short Type	A	Bmax	G
15	1/2	22.8	20.5	76	51	3	0.8	35
20	3/4	28.1	25.9	76	51	3	0.8	43
25	1	35.0	32.6	102	51	3	0.8	51
32	11/4	43.6	41.4	102	51	5	0.8	64
40	11/2	49.9	47.5	102	51	6	0.8	73
50	2	62.4	59.5	152	64	8	0.8	92
65	21/2	75.3	72.2	152	64	8	0.8	105
80	3	91.3	88.1	152	64	10	0.8	127
90	31/2	104.0	100.8	152	76	10	0.8	140
100	4	116.7	113.5	152	76	11	0.8	157
125	5	144.3	140.5	203	76	11	1.6	186
150	6	171.3	167.5	203	89	13	1.6	216
200	8	222.1	218.3	203	102	13	1.6	270
250	10	277.2	272.3	254	127	13	1.6	324
300	12	328.0	323.1	254	152	13	1.6	381
350	14	359.9	354.8	305	152	13	1.6	413
400	16	411.0	405.6	305	152	13	1.6	470
450	18	462.0	456.0	305	152	13	1.6	533
500	20	514.0	507.0	305	152	13	1.6	584
550	22	565.0	558.0	305	152	13	1.6	641
600	24	616.0	609.0	305	152	13	1.6	692

Stainless Steel Stub End Referenced Weight List

Nominal Size		SCH10S		SCH40S		SCH80S
DN	NPS	Short Pattern	Long Pattern	Short Pattern	Long Pattern	Short Pattern	Long Pattern
15	1/2	0.07	0.09	0.09	0.12	0.12	0.16
20	3/4	0.09	0.12	0.12	0.16	0.15	0.21
25	1	0.15	0.25	0.18	0.32	0.24	0.43
32	1-1/4	0.19	0.34	0.25	0.43	0.33	0.57
40	1-1/2	0.22	0.39	0.31	0.52	0.43	0.75
50	2	0.35	0.71	0.52	1.02	0.73	1.49
65	2-1/2	0.46	0.95	0.81	1.6	1.1	2.22
80	3	0.62	1.22	1.1	2.11	1.5	2.98
90	3-1/2	0.7	1.36	1.52	2.55	2.09	3.65
100	4	0.94	1.59	1.8	3.05	2.58	4.44
125	5	1.3	2.8	2.25	5.42	3.6	7.86
150	6	1.75	3.3	3.59	7.02	5.76	11.3
200	8	2.9	4.95	5.98	10.6	9.18	16.2
250	10	4.79	8.5	10.2	18.4	13.7	24.9
300	12	7.2	10.9	14.9	22.8	19.5	30.2
350	14	7.95	15	15.8	28.7	21.6	38.6
400	16	9.5	17.3	18.9	33.1	25.2	44.5
450	18	11.1	19.8	22	38	29.3	51.1
500	20	14.1	25.9	24.3	42.3	32.6	56.8
550	22	16.5	28.2	–	–	–	–
600	24	19.8	35	29.6	51.2	39.7	68.8

Features and Advantages

Convenient Connection

Good Sealing Performance

Strong Adaptability

Application and Precaution

ASME B16.9 stainless steel stub end is widely used in pipeline systems in industries such as petroleum, chemical, and natural gas. Especially in situations that require frequent disassembly and maintenance, such as oil refineries, chemical plants, and natural gas transmission pipelines.

Choose the Appropriate Material

Pay Attention to Size Matching

Adhere to Manufacturing Standards

ASME B16.9 stainless steel stub end is an important type of pipeline connector, widely used in industries. Understanding its definition, classification, materials, specifications, manufacturing standards, and application precautions is of great significance for ensuring the safe operation of pipeline systems.

The post Application of Stainless Steel Stub End appeared first on Quality Manufacturer of Industrial Pipe Fittings.