Metric Threads - Coarse Thread Pitches Size Nominal Clearan Diameter Pitch1) ce Drill Tap Drill (mm) (mm) (mm) (mm) M 1.60 0.35 1.8 1.25 M 2.00 0.4 2.4 1.6 M 2.50 0.45 2.9 2 M 3.00 0.5 3.4 2.5 M 3.50 0.6 3.9 2.9 M 4.00 0.7 4.5 3.3 M 5.00 0.8 5.5 4.2 M 6.00 1 6.6 5 M 8.00 1.25 9 6.8 M 10.00 1.5 12 8.5 M 12.00 1.75 14 10.2 M 14.00 2 16 12 M 16.00 2 18 14 M 20.00 2.5 22 17.5 M 22.00 2.5 25 19.5 M 24.00 3 27 21 M 27.00 3 30 24 M 30.00 3.5 33 26.5 M 36.00 4 40 32 M 42.00 4.5 46 37.5 M 48.00 5 53 43 M 56.00 5.5 62 50.5 M 64.00 6 70 58 M 68.00 6 74 62 Metric Threads - Fine Thread Pitches Size Nominal Diameter Pitch1) Tap Drill (mm) (mm) (mm) M 1.0x0.2 0.2 0.8 M 1.1x0.2 0.2 0.9 M 1.2x0.2 0.2 1 M 1.4z0.2 0.2 1.2 M 1.6x0.2 0.2 1.4 M 1.8x0.2 0.2 1.6 M 2x0.25 0.25 1.75 M 2.2x0.25 0.25 1.95 M 2.5x0.35 0.35 2.1 M 3x0.35 0.35 2.6 M 3.5x0.35 0.35 3.1 M 4x0.5 0.5 3.5 M 4.5x0.5 0.5 4 M 5x0.5 0.5 4.5

M 5.5x0.5 M 6x0.75 M 7x0.75 M 8x0.75 M 8x1.0 M 9x0.75 M 9x 1 M 10x0.75 M 10x1 M 10x1.25 M 11x0.75 M 11x1 M 12x1 M 12x1.25 M 12x1.5 M 14x1.0 M 14x1.25 M 14x1.5 M 15x1 M 15x1.5 M 16x1 M 16x1.5 M 17x1.0 M 17x1.5 M 18x1.0 M 18x1.5 M 18x2.0 M 20x1.0 M 20x1.5 M 20x2.0 M 22x1.0 M 22x1.5 M 22x2.0 M 24x1.0 M 24x1.5 M 24x2.0 M 25x1.0 M 25x1.5 M 25x2.0 M 27x1.0 M 27x1.5 M 27x2.0 M 28x1.0 M 28x1.5 M 28x2.0 M 30x1.0 M 30x1.5 M 30x2.0

0.5 0.75 0.75 0.75 1 0.75 1 0.75 1 1.25 0.75 1 1 1.25 1.5 1 1.25 1.5 1 1.5 1 1.5 1 1.5 1 1.5 2 1 1.5 2 1 1.5 2 1 1.5 2 1 1.5 2 1 1.5 2 1 1.5 2 1 1.5 2

5 5.2 6.2 7.2 7 8.2 8 9.2 9 8.8 10.2 10 11 10.8 10.5 13 12.8 12.5 14 13.5 15 14.5 16 15.5 17 16.5 16 19 18.5 18 21 20.5 20 23 22.5 22 24 23.5 23 26 25.5 25 27 26.5 26 29 28.5 28

M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M

30x3.0 32x1.5 32x2.0 33x1.5 33x2.0 33x3.0 35x1.5 35x2.0 36x1.5 36x2.0 36x3.0 39x1.5 39x2.0 39x3.0 40x1.5 40x2.0 40x3.0 42x1.5 42x2.0 42x3.0 42x4.0 45x1.5 45x2.0 45x3.0 45x4.0 48x1.5 48x2.0 48x3.0 48x4.0 50x1.5 50x2.0 50x3.0 52x1.5 52x2.0 52x3.0 52x4.0 55x1.5 55x2.0 55x3.0 55x4.0 56x1.5 56x2.0 56x3.0 56x4.0 58x1.5 58x2.0 58x3.0 58x4.0

3 1.5 2 1.5 2 3 1.5 2 1.5 2 3 1.5 2 3 1.5 2 3 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 1.5 2 3 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4

27 30.5 30 31.5 31 30 33.5 33 34.5 34 33 37.5 37 36 38.5 38 37 40.5 40 39 38 43.5 43 42 41 46.5 46 45 44 48.5 48 47 50.5 50 49 48 53.5 53 52 51 54.5 54 53 52 56.5 56 55 54

M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M

60x1.5 60x2.0 60x3.0 60x4.0 62x1.5 62x2.0 62x3.0 62x4.0 64x1.5 64x2.0 64x3.0 64x4.0 65x1.5 65x2.0 65x3.0 65x4.0 68x1.5 68x2.0 68x3.0 68x4.0 70x1.5 70x2.0 70x3.0 70x4.0 70x6.0 72x1.5 72x2.0 72x3.0 72x4.0 72x6.0 75x1.5 75x2.0 75x3.0 75x4.0 75x6.0 76x1.5 76x2.0 76x3.0 76x4.0 76x6.0 80x1.5 80x2.0 80x3.0 80x4.0 80x6.0 85x2.0 85x3.0 85x4.0

1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 1.5 2 3 4 6 1.5 2 3 4 6 1.5 2 3 4 6 1.5 2 3 4 6 1.5 2 3 4 6 2 3 4

58.5 58 57 56 60.5 60 59 58 62.5 62 61 60 63.5 63 62 61 66.5 66 65 64 68.5 68 67 66 64 70.5 70 69 68 66 73.5 73 72 71 69 74.5 74 73 72 70 78.5 78 77 76 74 83 82 81

M 85x6.0 M 90x2.0 M 90x3.0 M 90x4.0 M 90x6.0 M 95x2.0 M 95x3.0 M 95x4.0 M 95x6.0 M 100x2.0 M 100x3.0 M 100x4.0 M 100x6.0

6 2 3 4 6 2 3 4 6 2 3 4 6

79 88 87 86 84 93 92 91 89 98 97 96 94

Parallel (straight) Threads

BS parallel threads are also referred to as British Gas, British Pipe Parallel or Par Common symbols used for the thread: BSP, BSPP, BSSPI, BSPF, BSPG, PS, Rp, G

The BSPP (parallel) male will mate with a BSPP (parallel) female or a female port Usually marked: G size ISO Taper Threads BS taper threads are also referred to as British Standard Taper Pipe, Pipe Taper Common symbols used for the thread: BSPT, BSPTr, PT, KR, R, Rc Usually marked: Rc size ISO Characteristics of BSPT taper threads: tapered thread 1o47' truncation of roots and crests are rounded 55o thread angle pitch is measured in threads per inch taper is 3/4" per foot or 1 in 16 on the diameter Major Threads Diamete per Inch r TPI OD Pitch (inches) 28 0.3 28 0.38 19 0.52 19 0.66 14 0.83 14 0.9 14 1.04 14 1.19 11 1.31 11 1.65 11 1.88 11 2.12 11 2.35 11 2.59 11 2.96 11 3.46

Pipe Size (inches) 1/16" 1/8" 1/4" 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1-1/4" 1-1/2" 1-3/4" 2" 2-1/4" 2-1/2" 3"

NPT pipe threads - dimensions according ANSI/ASME B1.20.1

Common American National Standard Pipe Taper Threads NPT - National Pipe Thread Taper FPT - female (internal) National Pipe Taper threads MPT - male (external) National Pipe Taper threads NPTF - Dryseal American National Standard Taper Pipe Thread (ANSI B1.20.3)

For NPT threads a sealant compound or Teflon tape must be used for a leak-free

Characteristics of NPT (also known as ANSI/ASME B1.20.1 Pipe Threads, General tapered thread 1o 47' truncation of roots and crests are flat 60o thread angle pitch is measured in threads per inch Note! Pipe sizes do not refer to any physical dimensions. The outside diameter NPT - American Each thread size has a defined number of threads per inch - TPI, or pitch. The Standard Pipe Thread Taper 1) Nominal Outside Pipe Threads Diamete per Inch r Tap Drill TPI pitch OD (inches) (inches) 27 0.31 27 0.41 R 18 0.54 Jul-16 18 0.68 37/64 14 0.84 23/32 14 1.05 5/1/193 59/64 1/11/20 02 2 1/11/20 1.32 1/1/200 02 1.66 2 1/11/20 02 1.9 1-47/64 1/11/20 7/2/193 02 2.38 5/2/200 2 8 2.88 1/3/200 8 8 3.5 4 3/3/200 8 4 4 1/4/200 8 4.5 4 3/4/200 8 5 4 9/5/193 8 5.56 11/6/19 2 8 6.63 32 8 8.63 8 10.75 8 12.75 8 14

Pipe Size (inches) 1/16" 1/8" 1/4" 3/8" 1/2" 3/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 3-1/2" 4" 4 1/2" 5" 6" 8" 10" 12" 14"

16"

81)

16

The taper is 1/16 inch in an inch, which is the same as 3/4 inch in a foot (angle

NPT threads are not interchangeable with NPS - National Pipe Straight - threads.

NPT threads may look similar to ISO 7/1 threads. However, ISO and NPT threads ISO 7-1:1994 Pipe threads where pressure-tight joints are made on the threads Sponsored Links ISO 7-1 tapered threads are equivalent to DIN 2999, BS 21 (BS EN 10227-1), JIS tapered thread 1o47' truncation of roots and crests are rounded 55o thread angle pitch is measured in threads per inch Note! Pipe sizes do not refer to any physical dimensions. The outside diameter ISO 7-1 Tapered Threads e Outside betwee Pipe Threads Diamete n Size per Inch r threads TPI (inches) pitch OD (inches) (inches) 1/16" 28 0.312" 0.036" 1/8" 28 0.402" 0.036" 1/4" 19 0.532" 0.053" 3/8" 19 0.677" 0.053" 1/2" 14 0.838" 0.071" 3/4" 14 1.060" 0.071" 1" 11 1.327" 0.091" 1-1/4" 11 1.669" 0.091" 1-1/2" 11 1.902" 0.091" 2" 11 2.374" 0.091"

ISO 7-1 threads are not interchangeable with ISO 228/1 Parallel Pipe Threads. NP

as, British Pipe Parallel or Parallel Fastening Thread.

SSPI, BSPF, BSPG, PS, Rp, G

allel) female or a female port.

dard Taper Pipe, Pipe Taper or Conical Thread. PT, KR, R, Rc

Pipe Thread (ANSI B1.20.3) must be used for a leak-free seal. For NPTF no sealant is needed for a sealing.

1.20.1 Pipe Threads, General Purpose):

sions. The outside diameter of a pipe or fitting must be measured and compared to a table for size identifica

er inch - TPI, or pitch. The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI and OD of the thread a

e as 3/4 inch in a foot (angle 1o 47')

ional Pipe Straight - threads.

wever, ISO and NPT threads should not be mixed. ISO threads have 55o taper angle versus 60o for NPT. The

de on the threads

, BS 21 (BS EN 10227-1), JIS B0203. Characteristics of ISO 7-1 tapered threads:

sions. The outside diameter of a pipe or fitting must be measured and compared to a table for size identifica

28/1 Parallel Pipe Threads. NPT threads may look similar to ISO 7/1 threads. However, ISO and NPT threads sh

d to a table for size identification. A 3/4" NPT pipe thread has an outside diameter - OD - of

e TPI and OD of the thread are required for positive identification of thread size because more than one size

ngle versus 60o for NPT. The NPT root and crest configurations are also different from ISO. For ISO threads p

d to a table for size identification. A 3/4" ISO 7-1 pipe thread has an outside diameter - OD - of 1.060 inches.

ever, ISO and NPT threads should not be mixed. ISO threads have 55o taper angle versus 60o for NPT. The N

er - OD - of 1.050 inches.

because more than one size have the same TPI.

from ISO. For ISO threads pitch is usually measured in millimeters (may be expressed in Inch). The pitch are

meter - OD - of 1.060 inches. Each thread size has a defined number of threads per inch - TPI, or pitch. The 3/

gle versus 60o for NPT. The NPT root and crest configurations are also different from ISO. For ISO threads pitc

ressed in Inch). The pitch are different.

per inch - TPI, or pitch. The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI and OD of the thread a

rom ISO. For ISO threads pitch is usually measured in millimeters ( may be expressed in Inch). The pitch are

he TPI and OD of the thread are required for positive identification of thread size because more than one size

essed in Inch). The pitch are different

because more than one size have the same TPI.

Thread designations and standards for threads used in piping and fluid connectors

Straight Pipes Standards NPSC - American Standard Straight Pipe Threads in Pipe Couplings Coupli

Applicable Standards ANSI B1.20.1 PIPE THREADS, GENERAL PURPOSE (INCH) FED-STD-H28/7 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 7 NPSF - Dryseal American Standard Fuel Internal Straight Pipe Threads

Applicable Standards SAE J476 DRYSEAL PIPE THREADS ANSI B1.20.3 DRYSEAL PIPE THREADS (INCH) FED-STD-H28/8 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 8 NPSI - Dryseal American Intermediate Internal Straight Pipe Threads

Applicable Standards SAE J476 DRYSEAL PIPE THREADS ANSI B1.20.3 DRYSEAL PIPE THREADS (INCH) FED-STD-H28/8 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 8 NPSM - American Standard Straight Pipe Threads for Free-Fitting Mechan

Applicable Standards ANSI B1.20.1 PIPE THREADS, GENERAL PURPOSE (INCH) FED-STD-H28/7 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 7 Taper Pipe Standards ANPT - Aeronautical National Taper Pipe Threads

Applicable Standards MIL-P-7105 PIPE THREADS, TAPER, AERONAUTICAL NATIONAL FORM, SYMBOL ANP NPT - American Standard Taper Pipe Threads for General Use

Applicable Standards ANSI B1.20.1 PIPE THREADS, GENERAL PURPOSE (INCH) FED-STD-H28/7 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 7 NPTF - Dryseal American Standard Taper Pipe Threads

Applicable Standards SAE J476 DRYSEAL PIPE THREADS ANSI B1.20.3 DRYSEAL PIPE THREADS (INCH) FED-STD-H28/8 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 8 PTF - SAE Short - Dryseal SAE Short Taper Pipe Threads PTF - SAE Short is mainly used in low pressure pneumatic and fuel applications. Applicable Standards

ANSI B1.20.3 DRYSEAL PIPE THREADS (INCH) PTF SPL Short & SPL Extra Short - Dryseal Special Short Taper Pipe Thread

Are used in some pneumatic components where shortened thread depth is required

Applicable Standards ANSI B1.20.3 DRYSEAL PIPE THREADS (INCH) AWWA - American Water Works Association ANSI/AWWA C800-05 UNDERGROUND SERVICE LINE VALVES AND FITTINGS Unified Thread Standards UN - Unified Constant Pitch Threads (standard series: 4, 6, 8, 12, 16, 20, 2 Applicable Standards ASME B1.1 UNIFIED INCH SCREW THREADS (UN & UNR THREAD FORM)

FED-STD-H28/2 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 2 UNC - Unified Coarse Threads

Applicable Standards ASME B1.1 UNIFIED INCH SCREW THREADS (UN & UNR THREAD FORM) FED-STD-H28/2 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 2 UNEF - Unifed Extra Fine Threads

Applicable Standards ASME B1.1 UNIFIED INCH SCREW THREADS (UN & UNR THREAD FORM) FED-STD-H28/2 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 2 UNF - Unified Fine Threads

Applicable Standards ASME B1.1 UNIFIED INCH SCREW THREADS (UN & UNR THREAD FORM) FED-STD-H28/2 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 2 UNS - Unified Special Pitch Threads Applicable Standards ASME B1.1 UNIFIED INCH SCREW THREADS (UN & UNR THREAD FORM) SCREW-THREAD STANDARDS FOR FEDERAL SERVICES-SEC. 3 UNJ - Unified Controlled Root Radius Threads

Applicable Standards ANSI B1.15 UNIFIED INCH SCREW THREADS (UNJ THREAD FORM) FED-STD-H28/4 SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 4 Metric Thread Standards M - Metric Screw Threads M profile Applicable Standards ISO 261 ISO GENERAL PURPOSE METRIC SCREW THREADS - GENERAL PLAN ASME B1.13M METRIC SCREW THREADS: M PROFILE

FED-STD-H28/21 METRIC SCREW-THREADS M Keg Metric Taper Threads Mainly used in Germany.

Applicable Standards DIN 158-1 METRIC EXTERNAL TAPER SCREW THREADS AND MATING INTERNAL PA DIN 158-2 METRIC EXTERNAL TAPER SCREW THREAD AND MATING INTERNAL PAR BSi - British Standards R (BSPT) - British Standard Taper Pipe Threads, External Applicable Standards BS 21 PIPE THREADS FOR TUBES AND FITTINGS WHERE PRESSURE-TIGHT JOINTS ISO 7/1 PIPE THREADS: DESIGNATION, DIMENSIONS/TOLERANCES Rc (BSPT) - British Standard Taper Pipe Threads, Internal Applicable Standards BS 21 PIPE THREADS FOR TUBES AND FITTINGS WHERE PRESSURE-TIGHT JOINTS ISO 7/1 PIPE THREADS: DESIGNATION, DIMENSIONS/TOLERANCES Rp or G (BSPP) - British Standard Pipe (Parallel) Threads

Applicable Standards BS 2779 PIPE THREADS FOR TUBES & FITTINGS WHERE PRESSURE-TIGHT JOINTS A ISO 228/1 PIPE THREADS PT 1: DESIGNATION, DIMENSIONS, TOLERANCE Japanese Standards PF - JIS Parallel Pipe Threads

PF threads are functionally interchangeable with BSPP. This is an old designations r Applicable Standards JIS B 202 PARALLEL PIPE THREADS ISO 228/1 PIPE THREADS PT 1: DESIGNATION, DIMENSIONS, TOLERANCE PT - JIS Taper Pipe Threads

PT threads are functionally interchangeable with BSPT threads. This is an old design Applicable Standards JIS B 0203 TAPER PIPE THREADS ISO 7/1 PIPE THREADS: DESIGNATION, DIMENSIONS/TOLERANCES PS - JIS Parallel Internal Pipe Threads (to mate with PT threads) Applicable Standards JIS B 0203 TAPER PIPE THREADSPiping thread standards

Thread Standards

Most piping threads are produced to national or industry group standards describing threads form - threads angle, pitch and diam ANSI/ASME B1.1-1989, Unified Inch Screw Threads (UN and UNR Thread Forms)

ANSI/ASME B1.20.1-1983 (R1992), Pipe Threads, General Purpose (Inch) DIN 2999, Pipe threads for tubes and fittings - parallel internal thread and taper external thread ISO 261, ISO general-purpose metric screw threads Pitch

In general pitch refers to threads per inch for fractional screw threads and pipe threads. For metric screw threads pitch refers to th

Piping ThreadsCommon piping thread standards in the United States are

NPT - American Standard Pipe Taper Thread (also known as ANSI/ASME B1.20.1) NPSC - American Standard Straight Coupling Pipe Thread NPTR - American Standard Taper Railing Pipe Thread NPSM - American Standard Straight Mechanical Pipe Thread NPSL - American Standard Straight Locknut Pipe ThreadOther common piping thread standards

ISO 7/1 Tapered Pipe Threads - also known as DIN 2999, BSP 21, JIS B0203 ISO 228/1 Parallel Pipe Threads - equivalent to DIN ISO 228/1, BSP PL, JIS B0202, G 1/8 and G 1/4 BSP British standard pipe thread - British standard BS 21Tapered threads are for joining and sealing and straight threads are only for joining

uid connectors

pe Couplings Couplings

L SERVICES SECTION 7 PIPE THREADS - GENERAL PURPOSE ght Pipe Threads

L SERVICES SECTION 8 DRYSEAL PIPE THREADS ht Pipe Threads

L SERVICES SECTION 8 DRYSEAL PIPE THREADS Free-Fitting Mechanical Joints for Fixtures (these threads fit freely over NPTF threads. They are use

L SERVICES SECTION 7 PIPE THREADS - GENERAL PURPOSE

AL FORM, SYMBOL ANPT, GENERAL REQUIREMENTS

L SERVICES SECTION 7 PIPE THREADS - GENERAL PURPOSE

L SERVICES SECTION 8 DRYSEAL PIPE THREADS

d fuel applications.

ort Taper Pipe Threads

hread depth is required because of size limitations.

ES AND FITTINGS 4, 6, 8, 12, 16, 20, 28, 32)

READ FORM)

L SERVICES SECTION 2 UNIFIED INCH SCREW THREADS-UN AND UNR THREAD FORMS

READ FORM) L SERVICES SECTION 2 UNIFIED INCH SCREW THREADS-UN AND UNR THREAD FORMS

READ FORM) L SERVICES SECTION 2 UNIFIED INCH SCREW THREADS-UN AND UNR THREAD FORMS

READ FORM) L SERVICES SECTION 2 UNIFIED INCH SCREW THREADS-UN AND UNR THREAD FORMS

READ FORM)

L SERVICES SECTION 4 CONTROLLED RADIUS ROOT SCREW THREADS, UNJ SYMBOL

- GENERAL PLAN

D MATING INTERNAL PARALLEL SCREW THREADS - PART 1. NOMINAL SIZES, LIMIT DEVIATIONS, LIMITS OF SIZE A MATING INTERNAL PARALLEL SCREW THREADS - PART 2. GAUGING SYSTEM, USE OF GAUGES, CALCULATION OF

ESSURE-TIGHT JOINTS ARE MADE ON THE THREADS (METRIC DIMENSIONS)

ESSURE-TIGHT JOINTS ARE MADE ON THE THREADS (METRIC DIMENSIONS)

ESSURE-TIGHT JOINTS ARE NOT MADE ON THE THREADS (METRIC DIMENSIONS) , TOLERANCE

s an old designations replaced with G.

, TOLERANCE

ds. This is an old designations replaced with and R and Rc.

T threads)

orm - threads angle, pitch and diameter. Common standards are

taper external thread

etric screw threads pitch refers to the distance between threads.

JIS B0202, G 1/8 and G 1/4 etc.

hreads. They are used in swivel nuts of 07 adapters)

ONS, LIMITS OF SIZE AND VERIFICATION GES, CALCULATION OF GAUGE DIMENSIONS AND GENERAL FEATURES